Pros: Once set up, you don't have to mess with the straps again until you buy new boots or have to drop the highbacks down for transport. However, there are more than a few ways to alleviate this issue very easily. Speed of entry is also a major factor. This is especially useful for local hills where the mountain isn't as big so you don't have to constantly restrap your bindings. It is also a huge benefit for bigger riders. Flow's upper tier of bindings, NXT's, are among some of the lightest bindings on the market. The major selling point of Flow bindings for me personally is the even pressure distribution on my foot. I have 0 pain when riding Flows all day long (that's what she said). They are comfortable.
Cons: While Flows are plenty responsive, traditional straps still provide better response. If you are a fan of toe caps as I am, then that is also another downfall of Flows since they do not offer toe caps. Flows tend to have hardware issues, but that is generally the case with any binding. You'll hear more about Flow because it is obviously a more popular binding like Burtons. However, obtaining an extra set of hardware when you purchase your new Flows will solve this issue quickly. As with any binding, you should always check the hardware before you use it. You can obtain free backup hardware from Flow customer service. They'll send some out to you.