my first spotting scope had an angled eyepiece. Never would give me a good sight picture while wearing glasses. Later on I tested about twelve or fifteen scopes in the heat of the day over black top. I was looking for less mirage and distortion along with better resolution. I ended up with a strait instead of an angled scope. I also found that fixed power eyepieces (prime) had better resolution and less distortion. The best scope I've ever looked thru was a Swarovski. The next rung on the ladder would be filled with the Liecas, Kowas, a very high end Nikon, and the samething in a Bushnell. All these scopes were well over $1,000 except for the Kowa ($750). Course now they're even higher priced. I found that most all scopes above 45x were somewhat dim, if not down right dark. Dividing the power level into the lense diameter shows some real ugly things in many scopes (that's known as the light factor), and will give you an idea how bright they are. Ideally we want something like a 3.0, but thats hard to come by most of the time. The Kowa I use is 3.03, but with the 45x eyepiece it drops down to 1.8. Barely minimal for most of us. A 60x eyepiece would give you 1.36, and that's rather dark! The Lieca I used in my hunt for a new scope was very nice, but had a little more glare in the sight picture than I liked. Plus I don't think they are water proof or shock proof. The Nikon was very good in the lower ranges of power, but liked the resolution of the Kowa a little better. The Lieca was more fatiguing to look thru in bright light than the others. I saw little difference between the Bushnell and the Nikon.
gary