I just bought the QHY183M. The build quality is excellent and hooks up nicely to their filter wheel too, without another power/usb cable. I have been using ASCOM and X2 driver (for TheSkyX). The current X2 driver gives me a problem but the ASCOM driver seems reliable in TSX and SGP. There is a small user interface gremlin with the driver settings, which was introduced in the last version. It can be got round and I am sure will get fixed on the next iteration.