Very expensive, but they are a better fit for me than anything else I’ve tried so I’ve stuck with them. The knees go a little bit baggy pretty quickly, but then don’t get any worse, and I can keep a pair going for several days. I’ve got a pair each of Heroes, Fives, and Bulletproofs. the Heroes are my favourites, but in winter the heavyweight Bulletproofs are great for my commuting pattern, with a short bike ride at either end of a train journey.
The free returns thing is good. I bought multiple pairs to try different fits, and it was very easy to send back the ones I didn’t want.
Overall I’d find it hard to recommend them because of the price, and if you’re a normal shape you’ll be better off elsewhere. But if they happen to be suited to your particular configuration they may well be worth it.