I like full sized keyboards, even though I know that makes me kind of an oddity here. Maybe it's just because I have really broad shoulders, but I never really prefer having my mouse closer to my typing area. Even when I use a 60% or TKL board and try to put them close together, I'll naturally move my mouse over farther and farther right, until they're shoulder width or farther. I also use the numbpad quite a bit for my homework, as I'm a physics and math double major. I also do a lot of gaming, and when I game I defiantely find it more comfortable to keep my arms spread farther apart for that.
My ideal keyboard form factor would probably be the same as a model m13, with fn shortcuts like the HHKB. I always miss that arrow diamond on the m13, I swear I'd almost move my wrists if I had it. But yeah, a set up like that seems like the best of both worlds.