I've been using a Quark chromosphere now since May and just wanted to share what an absolute delight this piece of equipment is (albeit I never seem to have enough cloud free sky to get it right on band). I had been using a ST80 but felt this was lacking and not a great match for the Quark in terms of focal length. I've since moved to a 120mm refractor and hope the images show how capable the Quark is.