I have a GP2X Caanoo, I loved it, but I didn't get the most out of it for it still lacked that extra processing power needed to run SNES games full speed.
That had a 533Mhz ARM(?) processor, overclockable to around 750mhz safely and then a bit more. If you wanted transparency in your SNES games then not much luck.
This GCW Zero appears to have a 1Ghz MIPS processor and it seems to be doing, well fantastically.
On top of just having a nicer looking design and form factor, with an actual d-pad for primary input, it has Gmenu2X as the primary front-end, this device does look really attractive to me, but I don't want to fall into the same trap of buying an open-source handheld I end up shelving after losing interest.
Though I'm more hopeful about this one, but if their kick starter doesn't go well then maybe nobody will get these. :\
I dunno man, I dunno. I'd love one but...