Proform 750 Treadmill great way to burn calories..Speed and Incline are worth talking about. Most treadmills can go up to about 10 miles per hour and a 10 degree incline. Don't let speed or incline become a deciding factor unless you're doing a lot of high speed or high incline training. Obviously, electronically controlled speed and incline are the way to go. If those feature are manual just move on.