I am a huge runner and have experience on multiple treadmills. This is by far one of the best ones I have used. It runs really smooth and gives you a great workout. It has multiple features that allow you to constantly mix your workout up. Therefore, you do not get as bored while using it as you do on other treadmills. The track runs smoothly underneath your feet and keeps it easier on your knees. It is definitely expensive to own it, but it is worth the price. Any treadmill is expensive but this one is very high quality. I would definitely recommend this if you are looking for a great run indoors. I have loved owning mine. Performance The performance is great. It has multiple features and allows you to do multiple workouts on it. Comfort The comfort level is great. It is the easiest one I have experienced when it comes to me knees. Ease of Use It is easy to use and the features are easy to use once you learn how to do it all. Durability Mine has held up really well for the past year.