I set up the William Optics SpaceCat 51 with my color imaging train--ZWO ASI071MC, OAG, QHY guide cam--to test out focusing and test sequences in SGP, running through M31, M33, and M45 before the moon rose and washed out the sky. Seeing was not that great last night, but it was clear enough for testing. The Cat51 is such an easy scope to work with. I used the Frame and Focus panel in Sequence Generator Pro, and in a couple minutes had really sharp stars with a dialed in HFR. I went through the next five hours of imaging without adjusting focus.
Here's my setup for color imaging: William Optics SpaceCat51 250mm FL, f/4.9, ZWO ASI071MC cooled color camera, Orion Thin Off-axis Guider, QHY 5iii178 guide camera, iOptron CEM25P mount.