I can't speak for anyone else, but I personally chose the 250 over the other models for the extra "elbow room" that the poles seem to help create.
I owned a North American model previously, but I'm a big dude and needed a bit more room, width-wise. The NA was starting to affect me with a bit of shoulder squeeze. During the "buggiest" times of year here in South Florida the mosquitoes would also drive me mad, so I wanted something that kept the sides a little further away from me. The mosquitoes sit on the netting and wait for me to roll over in my sleep and press up against it.