The $700 additional from the x24 is steep, but I think the features it offers over the x24 make it worth is. I am replacing a Peloton, so if I am going to do it, I am going to have drop bars or I am just not going to do it.
The Zwift bike is not an option because of the exposed chain…unless there is an easy way to fix that.
I think that just means that it’ll vary resistance according to grade, using whatever algorithm they have for calculating or approximating the resistance necessary, based on your weight (hopefully) and height (maybe….to help approximate CdA) and of course, grade.
The only thing that actually changes is resistance. But as @Robin says, there will be some algorithm that links the (virtual) gradient and (virtual) gear choice to the resistance, to simulate riding at that gradient in that gear.
If you want the bike to actually tilt up, you need to buy a frame, turbo trainer, and gradient simulator (Wahoo Climb; Tacx Alpine; Elite Rizer) all separately.
I’d be wary of being locked into iFit. My partner’s treadmill just lost iFit support, and there’s no other way to connect to a tablet or use another app.