I personally love it. In my opinion, it was never meant to stick strongly to the back of the phone. Especially knowing that you need to remove the wallet from the phone to pull any of the cards out anyways (the thumb hole is on the side that sticks to your phone). That in mind, I think the magnets are at the perfect amount of strength. Strong enough to hold it in your hand and shake your phone without fear of it slipping off, but easy enough to push my finger and get it off if I want to grab my wallet while its in the pocket, but not take out my phone.
The lack of space for cards is concerning -- they say 3 cards, but if one of those is an Apple Card, things are super tight. I tried off-setting by doing Apple Card, regular Visa card and drivers license (thinner than a credit card) and it make it manageable, but still not much room for movement.