LifeSpan TR7000i

The last thing about this particular trend though is the warranty. You get a lifetime warranty on the frame and the motor, so the two things that are ...

I plan to put this treadmill in my game room, which will have a gaming computer, TV, electric fan, and the treadmill. I checked my circuit breaker and it says "15" on the switch. The requirement for the 7000i states "Requires a 115V NEMA 5-15 Non GFI Circuit." I'm hoping that's what that means?

As you noted, the TR7000i only has four compression shocks, whereas the TR6000i has eight, but with the higher weight capacity (400 vs 350 lbs) of the TR7000i, I wouldn't worry as much about longevity as I would comfort. Full commercial treadmills are designed more for durability in mind, rather than comfort, since they're ready for gym use.

It's big, heavy, and very gym-like quality. Never had any issues at all. My gym at home is all brand-name commercial equipment, and it has all lasted for years! Before this one, I had a Precor for 14 years.

TR7000iM - definitely overkill, but comes with an 18.5" screen, handrails, and a 5.0 HP AC motor that should last forever, non-folding full commercial, allows casting YouTube from a mobile device to the touchscreen. TR7000i - 3.5 HP AC drive motor, dated aesthetics, non-folding full commercial. TR6000i - one step down from the TR7000i, same dated aesthetics, light commercial, comparable to the 4TR. TR5500iM - folding, 4.0 HP DC drive motor, allows casting YouTube from a mobile device to the 10" touchscreen, would still meet your needs but the unit won't be quite as sturdy as the models above or the TRUE PS300, as it's a folding treadmill.

Then if you're willing to lubricate a belt, I think the best budget-friendly models with an AC motor would be something like the LifeSpan TR6000i, TR7000i, or TR7000iM. All three are on my shop. Obviously I'm biased, but they're nice machines.