I have owned my Pacemaster now for 3 years. I run a lot and normally use speeds from 8.0mph and up. I've down a few workouts where I've gone higher than 10mph and it's very sturdy and quiet. I recommend this treadmill if you and/or your family will be using it a lot. It'll last you awhile. I use to have a Proform and always had issues with that. (Posted on 11/26/08)