Hi,
I agree, straight scopes require more adjustments for sharing. But if your looking for the best scope for you as an individual and you agree with the concept. Then “straight” might be a better fit
Even for a single user, a straight scope requires more adjustments as soon as you pan or tilt the scope.
On my tiny straight Nikon ED50, the eyepiece extends ca. 140 mm behind the tripod screw, which depending on what adapter plate you use is on the pivot point or very close to it.
That means if you pan the scope, the eyepiece travels in a wide arc, and you need to position your head quite accurately behind a straight scope to get a good picture.
On the angled ED50A, not only is the eyepiece displacement smaller by about 30 mm, reducing the sweep of the arc, it's also much easier to place your eye in the best position by slightly varying seating angle, head inclination etc.
The same applies in tilt, where raising the line of sight by 10 degree inclination lowers the eye position by ca. 24 mm on the straight ED50, requiring an immediate adjustment in tripod extension to keep the same viewing position.
Again, it's much easier to adjust your body position to keep viewing with the same sight line raise on an angled scope as you're not committed to an upright body and head stance. The various back, neck, and eyeball angles give you several degrees of freedom with an angled scope, which is the reason pretty much everyone else here is in agreement that overall, observing with an angled scope is ergonomically more favourable.
(The arc in which the eyepiece sweeps is typcially greater for most straight scope than for my small Nikon ED50 ... as pointed out before, my girlfriend's straight Televid 77 is a lot longer than the Nikon, though I don't have it at hand to check the exact dimensions. A wider arc obviously requires greater adjustments and increases the disadvantage of the straight scope.)
Many of these same sportsman prefer straight scope, so they can switch back and forth regularly with less adjustment.
Most birders prefer angled scopes, for all the reasons already lined out in this thread and probably some more. I don't see any need to emphasize the experience of hunters, who pursue a quite different "sport" than birders, and from what I can tell from reading a limited sample of hunting-centric optics reviews, have quite their own ideas of what's important in optics.
When muscles are used, the amount of time you can glass comfortably is much shorter.
If you are staring at one spot for a prolonged period of time and don't pan or tilt, the straight scope might conceivably be (slightly) superior. However, I don't think that's a very common scenario for birders.
As soon as you start panning and tilting, you're moving, and you generate changing loads on a variety of muscles, allowing those that are momentarily relaxed to recover from the strain. That's different from your "weight lifting" model where the muscles are stressed continuously, which in fact doesn't really suit them well.
Due to the greater ease of adjustment of the body position to the viewing position with an angled scope, that's where the angled scope wins. Quite a few people here pointed out repeatedly that angles scopes are more convenient to use, and I think that's completely justified.
Regards,
Henning