Hey so, I've spent some time with both the gtab (few days with it) and the nook color(i own it), which has also been featured here in the past, i think. i prefer the nook color.
gtab advantages:
* faster standard clock processor (and i think it can overclock faster as well)
* enough oomph to play video
* bigger screen
* camera (no camera really sucks for nc)
* better bluetooth (for nook color, requires an updated ROM to activate bluetooth, while gtablet's is meant to work properly)
nook color advantages:
* with processor overclocked to 1.2 GHz, runs cm7 very smoothly with no lag, although video can lag a bit
* much more holdable--gtablet is really awkward to hold for long periods of time
* way higher quality IPS screen with fantastic viewing angles (the gtablet's screen angles are bad enough that you can't even get a full bright view of the entire thing if you hold it in portrait)
* this is also a screen note, but it's not as smudgy
* more accessories (i bought the cheapest leather cover for the nc on ebay and it works just fine, for the most part)
* CHEAPER (can be found for $160 refurbed these days)
at the end of the day, it's whatever you need in a tablet, but i think the nook color wins the day for me. but if the gtablet's what you want, this is a great price for it