I have been buying and trying all kinds of different NAS solutions. I have found very few that work reliably and can be trusted with storage of your critical information. I have a mixed OS environment (PC, Linux, Mac, Sun Unix). Here are the one's that I have bought and my experiences with them.
1. Snap server (several models). This is the most reliable and easiest to integrate into a Windows PC environment. As the name implies this is a real snap to install for PC. Not too easy for Linux or Mac but doable for an experiences networking specialist.
2. LanServer or Mediasonic HD9. This is a Linux OS and Samba server solution. Easy Install and to use on your PC, Linux and Mac network. These mini Linux based systems have major reliability issues. There are several restrictions for this class of NAS device. First is that the drive will be formatted in FAT32 and is not compatible with your PC once done. Linux Fat32 has extensions that make it incompatible with your PC. So if you plan to use this for a NAS and not a USB device be aware that once you format it for network storage, you can't go back and use this directly on your computer. There are limits on file size and file names. The max file size is 2 or 4 Gigs (depending on Linux implementation), the max file name size is 12 characters with 3 character file extension (12.3). If you exceed this limits is that there can
be erratic performance and reliability. Files can disappear or become
unaccessible without warning. They can be renamed to 8.3 format by the device. In some cases the file will disappear all together or they can become corrupt can not be erased or written over. Reformatting is the only way to recover the disk space. The file check routines are worthless and will not fix these problems.
3. Network Hard Disk HD363N or Triton. Different makers same issues as #2 for all the same reasons.
4. Ximeta NetDisk: This system is good as a USB device but as a network storage device the software is the limit here. To use this device as a NAS you must install a program that allows mounting on a PC network. This software is a network bandwidth pig. If you have more than one PC (not much of a network with only 1 PC) then you will find that most of your internal bandwidth will be lost to this software. This means that you will not be able to access the internet as fast as you could before you installed this device. Another limit is that if you buy this device as a case, not with a factory installed drive, you will find that you will have to practically destroy the case to replace the drive. This case in not intended for drive replacement.
5. Linksys routers and NAS devices. All are Linux based and have the same issues as #2.
6. Net Gear SC201. Same reliability and file limits as #2, plus you need to install special software. This software is not compatible with Windows XP-64 or Mac.
7. Maxtor MaxAttach. work well in a PC environment. No issues for all versions of Windows. I know that some models have max drive size limits but I have not tried upgrading the drives yet so I can't say for sure.