Good processor, bad prce to performance ratio
Firstly I upgraded my Santa-Rosa based Dell Latitude D630 from a T7300 to a T8300. So I got the Penryn architecture (better power efficiency, more performance per same clock), additional 400MHz and lost 1MB of cache (not a big deal, as it turns out). It was a huge improvement. A T8300 is faster than any T7xxx I could fit to a D630, eats less power. Windows 7 experience index had gone from 5.2 to 6.0. But I just couldn't live with 3MB of cache at that point, it somehow seemed that I'm not getting the performance I could get from my Dell Latitude D630 paired with a penryn (I edit & render videos with Sony Vegas x64) so I got the T9500, OEM version for a fortune.
T9500 runs at 2.6GHz - 200MHz faster than T8300, has 6MB of cache - twice as much. I was disappointed. It costed more than twice as much ($239), but was only a little bit faster. Windows 7 experience index now is 6.2. Sony Vegas render videos only a little bit faster. And it produces more heat and therefore uses more power than the T8300 did (not as much as my Merom based T7300 though - Penryn is still a Penryn). Those extra 3MB of cache just didn't make that difference I was expecting, I only felt those 200MHz. And that 6MB cache means larger die size and worse power comsumption (Penryn core for 6MB versions, Penryn-3M - for 3MB cpu versions).
So, while it's the fastest CPU besides the x9000 you can put into a Santa-Rosa based laptop, it's just not worth the price. If you want that cache badly, go for T9300. But I promise, the best choice is the t8300. It's efficient in every single way - price, performance (2.4GHz), power consumption (Penryn, 3MB cache). Just remember, Dual-Core i7 CPUs nowadays don't have more than 4MB of cache :)Read full review