If I was going to be only glassing with a spotting scope, I would probably run and angled just for comfort. When glassing all day long, they are just more comfortable.
I personally glass mostly through 15x binos on my tripod, then switch to a spotting scope for more power if I find something I need to check out. By using a straight eyepiece, I can lock down my head with the object in the center of my fov, remove the binos, put my spotter on backed down to 20 power and have the object in the fov without any adjustments. Then increase the power and fine tune to move the object to center if needed.
