I compared between the Swarovski 65MM HD, Swarovski 80MM HD, Zeiss 65MM and the Zeiss 85MM. I wanted to go to 60 power, and the Zeiss 65MM would only go to 45 power, so it wasn't a contender for what I wanted.
I went with the Zeiss 85MM. The Zeiss 85MM was brighter than the Swaro 80MM (because the bigger objective lense), shorter (therefore easier to pack) than the Swaro 80MM, lighter than the Swaro 80MM, weighed only about 3 ounces more than the Swaro 65MM, and was a whole lot brighter than the Swaro 65MM. Got to remember that at 60 power with the Swaro 65MM, your exit pupil is only about 1MM. So unless you are using it at anything less than noon on a sunny day, it won't be very bright and no amount of quality optical coatings is going to overcome that optical physics limitation. The Zeiss does seem to have more distortion around the fringes than the Swaros, but it wasn't very much and wasn't that big of deal to me as I tend to use the center of the field of view anyway. Colors with with Zeiss also seemed somewhat better. The Zeiss also was easier to use digiscoping with their camera holding device (but the Zeiss camera device might work on the Swaro - I didn't try). Lastly, the Zeiss was cheaper and seemed to be a better value when I compared what I spent for what I got. I am not trying to bad mouth Swaros - I own quite a few of their binoculars and their rangefinder. I am actually a big fan of Swarovski optics. I just thought the Zeiss spotting scope was overall better all things (size, brightness, cost, weight, digiscoping) considered IMO. But it boils down to personal preference (kind of like the Ford Chevy Dodge truck arguement).
The angled is the best way to go IMO. In addition to the other positive comments about angled already mentioned, they are much easier when you want to show your partner something. You don't have to get out from behind your tripod - just rotate the scope so he can see through it. Angled is also better (don't crane your neck as much) if what you are looking at (say up on a mountain) is much higher (or lower for that matter) than your elevation.