The thing with QB is that the rate of getting Match offers is fairly low. So there’s a certain amount of bitterness among students who don’t get an offer in the Match cycle, after getting their hopes up.
However, most of these students do very well in the RD cycle, and they can still apply RD through Questbridge to as many partner schools as they like. Some schools also allow unmatched QB applicants to convert to ED.
For the most part it’s a win, but you have to be prepared that you may not get that slam-dunk Match offer, especially if you only put T10 schools on your Match list.