Hmmm...
You DO NOT need more than 2 cores to run Gnome!
I don't even have more than 2 cores. I can run everything but high end games and graphics..but that's why god created the video game console. My interest in higher systems has more to do with compiling.
LXDE, XFCE, Gnome Classic 3.6 and below, I run these things on my Pi, which without getting too technical, I can assure you it is not equal to a dual core.
Ok, so..Gnome 3.8.
I have already mentioned that it is incompatible with the other Gnome bases..Mate, Cinnamon, Unity..so no need to fight myself, and no need to install those.
I started with Ubuntu-Gnome, because of that. Why start with problems I already know I am going to have?
I haven't gotten to Gnome-Panel(Classic/Fallback) yet, and I am not sure if I will install.
As an OS..Gnome 3..I really do not get why people like it. I may not care for Unity as a main OS..but..Unity started life as an add-on that people actually used..Gnome 3 doesn't have that advantage. It is not heavy, I think it runs around 250mb. A lot of little things don't seem to work, not enough to break the system,