Hasselblad has set the standard for precision when it comes to film plane and lens mount alignment. I've never seen a problem with it unless some amateur messed with it. In terms of mirror vibration the camera can be pre-released to only activate the leaf shutter for taking the photo. It's also a heavier system, which tends to be more stable when taking photos.
In the real world I don't think you'd be able to tell the difference. I like the Tessar equipped Rolleiflex because it's very lightweight. A 2.8 Planar Rolleiflex starts to get heavier, so might as well use a Hasselblad with the interchangeable lenses and the advantages of an SLR.
Wear and manufacturing differences will always, even with immaculate tolerances, be worse than a completely matched set.
F&H were not casual in that department.
Prerelease mirror means that you lose that half second, at least, between it and the decisive moment.
Not so with a TLR.
The form factor of the Hasselblad is more unwieldy than the Rolleiflex.
The latter can be held to your body for support. A Hasselblad will stick out from your belly or be held in a sideways stance.
It’s basically a shrunk down version of a camera shape that was meant for air reconnaissance.
The 3.5 Tessar was because more lens surfaces didn’t make much sense in medium format before coating.
And even with coating there was, as you say, weight and size advantages.
But even a 2.8 is still significantly smaller and lighter than a Hasselblad.
