I agree with UB on this one. If you are glassing for hours a day, it is more physically sound to be looking through a straight spotter with your head in the normal looking forward position. If you are looking through an angled piece, your head is bowed down and your neck can get very sore because you're holding your head up against gravity with your neck muscles instead of your bones.
Then there are the aquisition problems UB mentioned. But what UB didn't mention was the incident of the ram he actually shot last year. It was RUNNING along a ledge straight up above us about 800 feet higher than us. It required us to get ahead of it and keep the camera, the spotting scopes, and the shooter constantly moving with the ram just to keep up. Not only did it require a straight spotting scope for aquisition, it required a pistol grip bogen tripod head to keep the ram in the field of view. With an angles spotter, there absolutely would have been no chance of seeing this ram let alone getting this ram.
Then there are the packing and storage issues. The angled spotters require an oversized case or for you to remove the eyepiece every time you put it away. Pain in the arse! WIth my straight spotter, I simply remove the scope from the tripod, and throw it into my Crooked Horn Outfitters spotter/tripod case and go. If I had to unthread the eyepiece to make it fit in the case every time I used it I would go crazy!
If it's not far, it's boring.