SCG? Do you mean a Schmidt-Cassegrain like the Meade and Celestron offerings? They have thier hardest places when pointing to about 80deg and towards the zenith from the pole. At that point, the EP is pointed down under the forks and is just barely accessible to the user. By the time you hit zenith, the EP becomes quite accessible. Dobs have thier problem within about 10deg. of zenith. German Equatorial mount problems are primarily due to the fact that you have to swap the side that the scope lays on relative to the mount at some point in the sky. All mounts have a problem pointing in some way or another, it's just a matter of choice of which you are ammendable to.