I'm a 300lb rider and i use the profile airstrike bars. They fold up so you'd think they'd be a little more flimsy, but they actually rest on your bars when they fold down, so they have 2 points on contact when you're leaning on them. i've had them for about 2 or 3 years now and the only problem i've run into was the springs that keep the arm rests up giving out.... all that took was a quick call to profile and they shipped me out new springs, no questions asked.
i'm a big fan of these since they also allow me a few more positions to put my hands with the pads either up or down. it's a little bit of a gimic, but i kind of find it useful.