Did you buy your gtablet new? figure out which bootloader your tablet is on, 1.1 or 1.2. A new tablet will probably be 1.2. From there you can figure out which ROM. I have been on flashback and gtabcomb ROM's and fairly happy with both, before that I was on CM7. I haven't had any real issues with any of the ROM's really, and it's not difficult to switch between them. Hardest part is getting your apps and everything set up again.
This is a fairly reliable tablet with the custom ROM's, this was my first Android device and learned about recovery, nvflash and all of that stuff from this tablet. Switching bootlaoders was a bit easier then I thought it would be, there is a guide for everything with this tablet. Slatedroid forums are really good with this tablet too.