I am also coming from a 156 Agent, looking into the 152 Stairmaster, possibly 151 Evil Twin.
I am 5'11" 170 lbs, but cutting down to 155-160 for the summer...might keep it that way though.
Do you do any large jumps? That's something I probably will not do because I am getting old. I can do medium sized kickers but that's about it. Thanks for the landing comparison.