I have one that unbalances every scope I have tried it in, plus it really needs the safety groove because on a GEM the normal tube rotation as one slews puts enough torque on it to automatically point it to the ground. I am speaking of the 35mm. Scopos Extreme. It is not only heavy at 1090g. (38.2 oz.) but tall and wide as well. I have to move the Brandon forward about 2" when I put it in but it does have a nice sharp 70 degree field. I use it rarely because it feels so precarious but I love the 3.7 degree FOV. which is slightly larger but much darker than the 3.65 I get with the 48mm. Brandon ep. with its 50 degree field. I probably would be happier with the 36mm. Hyperion Aspheric. (Naglers and Pans are presently out of reach.)
It nearly doubles the weight of my WO 66 petzval but the 6 degree plus FOV is really nice.
Clear skies
Glenn