I’ve owned and used both, and prefer angled. Most of my spotting scope use is in mountains hunting Stone sheep, goats, caribou and the angled for me is more versatile in body positioning and comfort. It can be a little trickier to get on target, but a non issue in my experience. For me the versatility easily outweighs any difference.
If I was in flat terrain all the time, then maybe the angled wouldn’t have the advantage of versatility and straight may be a better choice for me.

I will add that one disadvantage I see in angled for backpacking is in the shape. In a full backpack, I find it easier to pack an angled spotter with the eyepiece removed.
When hunting with partial pack load, it’s no issue.

Last edited by mod7rem; 05/21/21.