The XT675 is Spirit’s top of the line. That means it is the most expensive (about $3,000), but also that it is big, heavy, and stable. It does not fold up and roll like less expensive models. It is an excellent treadmill for serious runners, big people, and those with plenty of room for storage. Its long 60” belt accommodates tall runners. Its 425 lb. weight capacity and 3.5 hp motor accommodates heavy users by providing the stability to feel safe. The machine itself weighs 264 lbs. The large 3 inch rear roller provides a smooth and quiet ride. The price includes a lifetime warranty on the motor and ten years for parts. The hitch is that labor is only covered for a year and you would want a pro to work on such a nice machine for you.