Owning the finest quality telescopes does not preclude one from being a good observer.
The same is true with a larger aperture as it is with a premium optic. In all scopes, detail is still visible at the limits of our acuity. By definition, I guess, a good observer knows how to detect that detail, recognizes it when we see it, and trusts what we see. In my view, when we talk about increasingly smaller differences in Strehl, this is what we mean. The important thing to seeing such detail is our observing conditions (seeing and transparency), scope preparation (collimation and thermal stability), and our experience. I'd prefer an excellent scope in lab-like observing conditions over the same excellent scope in average seeing, but a modest scope in favorable observing conditions is fine, too. Either with a skilled observer at the helm. We like what we see, that's what we need to know because we know what we like to see.
This is where high Strehl shines, to see slightly darker blacks, more definite boundaries between the slightest shades of grey, and splitting close unequal doubles. All great stuff, but not easy to see in any scope. If seeing get's in the way, forget it. In my experience, anyway. I have seen detail in the Martian polar cap, craters smaller than the Dawes limit, and albedo features on Ganymede to name a few through a modest refractor-size aperture of unknown Strehl. No matter how good the scope, none of that would have been visible if the seeing was not diffraction limited or better. A premium refractor can present the same detail as being a little cleaner to a good observer who get's lucky enough to see what their scope can do. Unfortunately, though, not under the jet stream even though seeing favors smaller apertures.
Edit: I guess my response to the OP is, sure, one can tell a difference. However, and like most things, so many variables make it difficult to say when and how much. Get a scope that pleases you, first off, and a better scope when you know what to look for, when your ready for it, and able and want to pay for it. And, by all means, pray for good seeing. Improving your skill will make every scope better until you reach the limits of the scope and your own acuity. Then get a bigger scope.
Edited by Asbytec, 07 May 2021 - 11:00 PM.