I purchased a steam shower on ebay in the fall of '06, and while the experience wasn't awful, there was a lot of information I wished I'd had prior to making the purchase.
It won't surprise you to learn that just about all of the steam shower offered on ebay are made in China. While there's nothing inherently wrong with that (almomst everything is made there these days), the problem here is that the manufacturers do not have a US presence. This means you are at the mercy of the seller for warranty coverage, or if something goes wrong during installation. Because of this you should not expect feedback for sellers of steam showers to be reliable. Similarly, don't believe quotes of list prices in the high thousands.
The shower I purchased was a 53" quarter round (installed in a corner) shower/steam/whirlpool unit with the manufacturer's name listed as "Koral" in the auction. However, there is no mention of the manufacturer anywhere on the product or the meager manual that came with it. I suspect this is a name made up by the seller. The shower ships in several cartons (the largest holds the tub, but the heaviest is the door glass). When I received I was at first impressed by the build quality, but this lessened as I unpacked further.
The movement of the doors on the tracks is not as smooth as a high-end shower door, but it's better than the base models that you get at Home Depot, and is more likely to stay on the track because it's locked in place. The tub is fiberglass, but the material is relatively thin. Construction quality is not nearly on par with a smaller Koehler whirlpool tub I have. Interestingly, the tub has several legs that need to be leveled; this is different than a standard tub which just sits on the floor or on some sort of aggregate. This is probably an advantage since you can adjust for uneven floors. However, again, the frame is fairly cheaply made. The walls sit on the edges of the tub (be sure to caulk) and then the cover sits on top of the walls. I had a contractor do the installation (part of our whole-house renovation) so I wasn't around for most of it, but here are a few notes (note that these will apply only to the tub I have, but hopefully you can extrapolate some useful info):
1) This tub required a 30 amp, 120V circuit. I am a dedicated DIYer so had no problem running a wire, but if you're putting this on the second floor and your circuit breaker panel is in the basement, it could be an issue for you. I believe larger tubs require a 220V circuit, which is really no more difficult to install. I highly recommend a GFCI circuit breaker, since you're mixing water and electricity here.
2) The drain connection is nonstandard, and probably isn't to US code. With a standard tub you plumb a 2 inch drain directly to your plumbing underneath the tub, using a P-trap. This drain connection has a flexible hose (similar to the type that is used with aboveground pools, but thinner) which will not connect up to any standard US plumbing without some creativity. I discovered that the inner diameter of the hose was the same as the outer diameter of 1" PVC pipe, so I connected a short piece of PVC to my drain system. However, due to the thinness of the hose, it does take a bit longer to drain than a standard tub. This the first bad design issue. It would not be possible to install a standard drain in this tub, at least not without a LOT of modifications.
3) All plumbing runs through the steam generator. Connection to your plumbing is via thin hoses with FIP connections. While it's not really standard for shower hookups, you can find the correct valves at Home Depot. However, here is bad design issue number two: since the hoses are fairly thin, it does not provide enough pressure to run the steam generator and the shower at the same time, which means you get a burst of hot water through the showerhead every time the steam generator turns on (about once a minute). If you think you're going to want to run the shower and steam generator simultaneously, I recommend running a separate cold water line (the steam generator uses the cold water supply) for the shower and capping off the output to the shower head from the steam generator.
4) The tub is not UL approved (although it is CE approved). Take that for what it's worth.
Here are some other problems I have with the unit's design:
1) The LCD display is almost useless. There is a 4 digit numeric display along with some silly animations (bouncing lights when the radio plays, and a picture of a woman with rising steam when the steam generator is on). However, rather than displaying something useful, like the time or the radio station frequency (which apparently can be shown, but it's not obvious how), it displays some sort of temperature reading (in Celcius only, no Fahrenheit). I have not yet been able to figure out the purpose of the temperature readout; it seems to be ambient temperature, but you can adjust it using the up/down buttons, so this absolutely makes no sense. In addition, some of the icons for the functions are not obvious.
2) The water selector that lets you choose between shower, rain, foot massage, tub (labelled "out put") and back spray has markings that indicated the selected function; however, there is NO pointer on the knob to indicate what function you've chosen. Lest you think you can add your own pointer to the knob, the diagrams around the knob are almost unreadable when it's dry, and become completely unreadable when they're wet. This might be a good time to break out the P-touch...
3)There is a fan in the ceiling, but it's useless, as it has almost no power. I don't even bother with it; I have a powerful fan in my bathroom ceiling, and it removes all the steam as soon as I open the shower doors.
4) The radio's sound quality is abysmal. While I wasn't expecting anything great, this is really awful. Think portable AM radio quality.
5) The whirlpool tub is not nearly as powerful as the pump in my American Standard whirlpool tub. This is a big disappointment.
Now, having said all this, I'm not totally unhappy that I bought this. The steam works well, and it's especially useful when I have a cold or my allergies are bad. The tub looks nice (it actually looks better set up in my house than it did in the pictures), and it was a pretty good deal when you consider you're getting a tub, surround, doors and shower body, all of which you'd probably have to buy separately.
After having used the shower for about a year, some updates:
1. The steam generator has gotten rusty inside, and drips rusty water when you start it. This happened about 6 months ago. I wrote the seller and they gave me some convoluted procedure for cleaning it out, which involved diluted citirc acid and disassembling the steam exit pipe. I tried it but the rust came back afterwards.
2. Both the handheld shower and the hose that connect it to the wall have broken. First, the selector on the stopped working and we were stuck with a single setting. Then the hose started to leak where it connected to the handheld, and one day just separated completely. Luckily it uses standard fittings so we were able to replace it with a WaterPik handheld unit. However, I would have expected it to last longer than a year.
3. The knob that controls the air in the whirlpool has loosened up, and I will have to pull out the shower in order to tighten it. Suggest you check this before installing.
4. The display has been somewhat flaky and stops responding to button presses. A reset of the circuit in which it's plugged into has cured it each time. This has happened maybe three times.
One more note: I've gotten several requests for more information from readers. While I don't mind answering these, please include your email address in your request, since ebay's email policy sometimes prohibits my responding to you through the internal messaging system.
1. A couple of months ago the display flaked out again. This time the GFCI circuit breaker (in my main circuit breaker panel) refuses to set, leading me to assume there's a problem in the electronics somewhere.
2. It has occurred to me that getting any parts or repair for this tub, once the warranty runs out, is going to be next to impossible. Break a piece of glass? Forget it. Even if you can find a glazier willing to cut (and drill, if necessary) the correct size piece, all the glass is tinted. If you don't match the tint exactly, it's going to be obvious. Also, any curved glass will not be practical to replace at all, since it would have to be custom made.
3. Any repairs to the electronics will require an electronics technician (NOT an electrician) who is willing to make house calls AND can work without a schematic or any telephone support. This will be difficult.
At this point, I cannot recommend any of these showers unless you can find a domestic distributor or rep who is willing to support you once the warranty runs out.