If you are into using the programs, it is well worth the $400 extra over the Go model. Lifefitness is arguably the best with their programs. With that said, they are arguably the worst about carrying over the quality from their club units to the home. These are Lifefitness in name only.
A solidly built unit with the creature comforts you expect with Lifefitness. Not a great treadmill but not bad either. Kind of like a turkey sandwich...great if you are really hungry. If you are hungry for a good machine, you will like True much better at the $3k price point. At this range, you have choices from Precor and you are within a few hundred of a base Landice unit so unless the Lifefitness name is a "must have" then we would go with one of the other brands.