I prefer off-screen buttons over on-screen ones myself, but I guess on a 5.5" screen it's not like I could complain too much about a bit of screen space being "wasted" with buttons. I'll more-than-likely use the capacitive buttons on the 1+1. All 3 of the Androids I've owned have the "back" button on the right, "home" in the middle, and "menu" on the left, and I was ecstatic to learn that the 1+1's capacitive buttons keep this arrangement, bucking the (non-Samsung) trend putting the "back" button on the left (which would drive me bonkers), and the "recent apps" button on the right. Although I'm sure CM11s would let you change them to do whatever you wanted anyway...
Relax, go nutz!