I purchased a ProForm XP StrideClimber 600 from Sears. The sales lady assured me this was a quality built machine. Since then it's constantly broken down. The parts are expensive and don't last. It's a shame because this machine really gave me a total work out. The welds break, the cast bearings break, the lower wheel bearings break apart, the plastic covers fall off, it clicks and clacks when I use it. I paid $550 dollars for this so called quality machine that just doesn't hold up. Don't buy one.