Rock solid and quiet
The running experience on this treadmill is excellent. The running surface has a nice feel, not overly squishy or bouncy like some treadmills. The frame is rock solid so with my 175 pound mass, there is no flexing, shifting, creaking, etc. I can do intervals at my personal top speed (reasonably fast, but not setting any world records) and feel comfortable that the motor and frame are well within their capabilities. The operation is also reasonably quiet. Even at high speeds I can hear the TV across the room, albeit with the volume a bit higher than normal. I don't know if the high-tech belt adjustment features deserve the credit, but I can say that I have never felt any belt slippage and that the run experience feels completely road-like. I paid for those features and have not been disappointed.
The user interface leaves something to be desired. For example, I wish I could easily program in my pace/time based interval workouts, hit go and then just run, but if it is possible, I have not been able to figure out how to do it. Other than the manual setting, the only program I find useful is the variety (variable elevation) program. Another gripe is after the workout is over, I can only see limited workout statistics. Importantly, I cannot see elevation gained. Again, perhaps it is possible to review this data somehow, but it is not intuitive and I have not figured out how to do so.
I have had no reliability issues, but I have owned it less than a year so I would not expect to have any. Installation was fine, not memorable, which is good, I guess.
Bottom line is that while the user interface could and should be better, it is easy to use in the sense of turning on and off and changing the speed and elevation on the fly. Most importantly, the run quality is outstanding.