If you are on Facebook, there is a dedicated Q'nique group to help with the research. There are definitely some folks who are on their 2nd and 3rd machine due to issues that they weren't able to resolve without sending the machine back to Grace.
Keep in mind if you are thinking of going with the 21, it is rumored that the 21 Pro will be coming out in the next month or so, at least based on the responses I got when I asked about it at the time the 15 Pro came out.