7mm remington express and the 280 are the exact same thing. it used to be called the 7mm remington express however when people started confusing it with the 7mm mag and sales weren't good they changed the name to 280 remington. at least this is what i have heard/read.

the 280 would be my choice over the 270 and 30-06. it can shoot heavior bullets then the 270 and holds a higher muzzle veliocity then the 270. it is a little faster then standard 30-06 loadings and dosen't drop as much at farther ranges.

if you ask me i think the only reason that the 280 didn't take off in sales is because you could get the 270 and it will shoot flatter or you could get the 06 and shoot heavior bullets.

i don't own a 280 but i really want one and i have shot them a lot in the past