I have been using the proform 650 for 3+ years averaging 6 times a week at 30-40 minutes a session. When I began I weighed 350# (max. suggested is 300# I believe) and I am now down to 295#. I don't have a single complaint though if I do purchase another treadmill down the line it would be programable to my needs. The current built in programs are more of a hassle than the manual ones. I have been fairly hard on the machine and it works as well today as it did when I bought it considering that I have probably put on around 2000 miles on it.