Never ran on the Trueform, but did run on the Woodway curved manual treadmill which looks nearly identical and is also a non-electrically powered treadmill as well as another one that looked nearly identical in a shop (forgot the brand).

Was very easy to run on, almost too easy as it speeds up immediately the momoent you start striding longer, with the tendency to make you run even faster. But with not too much practice I got the hang of it.

For me it felt a bit easier than normal outdoor running, which sort of surprised me, as I thought the need to self-power the belt would make it harder, but for me the curve of the TM made it harder to keep from speeding up automatically. Sprints (which I never do) are a piece of cake on this machine, I felt like the machine was built for sprints rather than endurance running.

I would definitely miss the lack of incline control that you get on a normal TM as well as the good erglike locked-on pace training you get with a normal TM.

The decks on both curved TMs I tried were REALLY nice. Like soft yet firm, and very quiet for the impact. Def premium items there.