So, I have had it out for two nights now. My general take is that it isn't perfect, but I'm not terribly disappointed either. That seems to be about balance for a scope positioned the way this one is in the market. The only lingering worry is how it will behave with the reducer once that is available, as that is one of the perks to this tube over some competing options.
The good: the field at f5.6 is quite flat, to the point of very minor FWHM shifts across the frame that look to be focuser sag. It is well illuminated, and the mechanical elements of the system seem to do their jobs (with a minor note below).
The so so: there is some minor chromatic aberration if you pixel peep. I think it may be slightly clearer due to my use of an Hutech NB1 filter during my shots, but it is there. It is easiest to pick out by looking at the isolated channels in Pixinsight, where both blue and green match well, but red is slightly narrower and elongated in the corners. This aligns fairly well with the spot diagram.
There is also a very slight amount of sag and image shift in the focuser. It is overall quite good, holding my camera steady without me locking it down, even at the zenith. I will try locking it for the next session to see if it improves the sag.
The slight tilt in the system produced some issues for the stars on the bottom left, which did not appear to be as bad on the second night. I've also observed similar distortion from the NB1 filter on my 100-400 lens at f5.6 and using my 105mm at 1.4, so I'm not quite as concerned about that just yet.
The mosaic below is a slightly cropped field from my Ra, so it is just between a full-frame and APSC field. I had to crop because the meridian flip killed the alignment in the stack. I will share a single frame example later.
Cheers,
Dan