I used to rent and I never had a problem with them, liked them a lot to be honest. Never had to stop to strap in, I could just reach down as I was coming off the lift and straight down the mtn I went. A lot of rental shops use those and step ins(which blow!). So maybe look at renting once and see how you like em.
This is my first year on Flows and so far I'm liking them. It used to be everyone waiting on me, now it's easy. And I think they're more comfortable. Just spend a solid day of riding and adjusting to get them where they are comfortable. Also don't buy the cheap Flows or you'll be dissapointed. Cheap bindings nomatter what brand are junk, get the NXTs or better.