I don't own Flows, so I can't personally say they are bad. I do know people who have them and they are far from what they're portrayed to be. I can actually strap in the same amount of time my friend can who has flows. Other than having the convenience factor they are not that great of bindings. I would look elsewhere, but it's up to you. It's you who is buying and riding it, not me. Many people on these forums will probably tell you the same thing too.
Well, that's one POV. Now for another. I own NXT-AT's and Fives. I also own or owned Burton Missions, Salomon something-or-others, and Cinch's. I'm an intermediate rider, and more of a downhiller than a park rat, so take that into account as well. Anyway, the Flows are from what I can tell exactly
what they're portrayed to be. I've not noticed a loss of responsiveness. In fact, over the course of the day the Flows are less likely to make my feet ache. The NXTs are better than the Fives, which is what you'd expect when you pay more. Actually the crappiest bindings were the Cinch's IMO. As far as strapping in, I come off the lift, kick my back foot in, and snap the binding shut without ever stopping, let alone sitting. I've never seen anyone with traditional bindings do that, although I suppose it's possible in principle.
The big problem with Flows if you're in the park a lot is not quick entry, but convenient entry in random situations. If you're on a moderate slope with Flows, you have to turn to face the hill to snap in. That's a PITA, and depending on the layout of your park you may find it much easier to sit and crank standard bindings.