I just defeat the first gym trainer and went to the cave.
I dont know that much about hacking but I've played Gold (actually Crystal). And it seems so different. The pokemon, the sprites, everything (and I'm just in the first gym so I think that there will be more things to see) is literally amazing.
Really a great job. This is the only game that makes me actually want to hack-rom myself, altough I probably wont do it because it must be really hard.
Absolutely enjoying it. Seriously, GREAT work.