Alright so I used my Flak all weekend. Played 36 holes at Waller Park in Santa Maria Saturday, and 27 at De LaVeaga. (here are some highlights from the weekend: http://www.youtube.com/watch?v=BMurarwrJ4w
Absolutely love the bag, my back was waaaaay less tired than normal. It felt super light, didn't bounce around. Getting the discs in an out of the main compartment was super easy, and no discs ever came out when they shouldn't have. The side disc pockets worked great, loved all the extra storage. The bag always stood up when I put it down (something I hear you can't say about Grip bags).
Problems: Ok so this is my only complaint so far. The straps that go from the bottom of the bag and connect to the backpack straps is too thin, and too short. Check out these pics. The pic where it's twisted is how it was most of the time.
When I'd put the bag on sometimes that strap would loosen up, and because they're a little short would go all the way to the end of the strap, this made it hard to tighten back up (not much to grab), so I ended up just keeping it at max length most of the time, which was OK, but I'd prefer it tightened up.
I think the strap needs to be longer (so there's more to pull), and wider so it fits the buckle.
Other than that they killed it with this bag. Awesome work HyzerBomb. If you're looking for a backpack style bag you won't regret getting a flak.