I thought this was a fascinating puzzle but shied away due to some of the negative video reviews I had seen on it. Well I finally purchased one, and it was better than I expected, but still not great. So 20 minutes later I had finally managed to take the puzzle apart. I carefully trimmed and lubricated all friction surfaces and reassembled. It took roughly 6 hours, so be patient if you want to attempt this. After full assembly the puzzle turned absolutely flawless. Do note that this is not a speed cube and is very picky for alignment (what do you expect with 264 external pieces and even more on the inside) Both the 2x2 moves and the megaminx turns work with little to no catching after trimming the pieces.
Long story short, lots of potential, but lots of work.