from what I have seen, the RASA can produce some pretty spectacular results in very short subs (As you would expect) but it is probably very demanding on being set up just so. Use a cheap adapter where the shoulders do not turn out to be quite parallel and the results will be endlessly frustrating.
I also would not consider one without a focus motor and automated focus for deep sky imaging instead of the EAA that lollywater is doing. I don't think the focus shift is likely to be as massive as the traditional SCT due to only having the one mirror instead of two curved mirrors which amplify any focus movement either in making focus adjustments or shifting focus due to temperature changes, but the sweet spot will also be F2 tiny instead of F10 (Or even F6.3) forgiving.
Images like this start to show some promise though the second one shows a little tilt or perhaps the spacing not being quite right. But it is based on 120 second subs!
https://www.astrobin.com/400996/B/
https://www.astrobin.com/hewusf/0/