Yes, flow is a common brand, but more experienced riders can and will tell you that Flow also lacks in the quality department. I'd never, EVER get a pair of flow bindings. They'll just break on me since I am a rather aggressive freerider. I've never tried out their boards, but I don't cheap out on my equipment. And from what I've seen, flow doesn't make the best boards either. They are low-end at best. Alot of people here are experienced riders who use nothing but high end equipment, which explains the lack of responses regarding this issue.
In snowboarding, you get what you pay for. You decide to cheap out on a board? The board might just cheap out on you.
This doesn't apply to Burton though... they tend to add an extra 150$ for the board just for the big B that is on it. I'm not saying burton doesn't make good stuff, quite the opposite. But they are generally overpriced.