Has a more compelling story than the T5.0 but if you are already at $4k, why not step up to the T7.0? Also with what True is offering in this range, I would take a hard look before plunking down $4200 on this one.
The warranty on the Lifefitness T5.5 is good. Labor is covered for 1 year, electrical and mechanical parts are covered for 7 years, the motor is covered for 10 years, and the frame and Lifespring shock absorbers are covered for life. This kind of coverage displays a good amount of confidence in this treadmill on the part of the manufacturer.