overall, sketchy reviews and CS from what i have seen.
imo, for the $....just buy a dedicated 22 rifle.....which will cost the same or likely even less than the mini 22 kit. (marlin 60, $160...10/22 $230ish).
i was considering a 22 conversion for my AR...then i thought, for about $50 more, just get a 10/22. i sure haven't regretted that decision!