Thanks Ross, it does seem like a decent little imager.
Before buying the Redcat I had my eye on the Sharpstar 61EDPH for a few months, a more conventional 60mm f/5.5 scope with a reducer bring it to f/4.5. I gave up waiting for the Sharpstar and ordered the Redcat, then two days later the 61EDPH became available, so one of those is turning up on Monday too
I'll post a test of the Sharpstar in the next week or so, weather permitting.