Re: D-930 monocular
I have experience with one. The housing is made by the same company that makes most of the D-740 / 760 scopes. The image quality will be very good provided you get a good tube.
The mounting system is not good, IMO. I have heard first-hand accounts of Leupy's breaking at the objective bell. It needs to mount just like the PVS-22, that's all there is too it. The thinking was, to allow guys to use these on bolt guns....deer rifles, so that the user could have a regular wood stocked gun with no rails.
I think its not a good idea, and its been the reason I don't own one.