Yay!! Park bags!!
I've never been a fan of the fanny pack. I've been known to wear one, but definitely not my first choice!
I got a VB hipster for my last trip, but found that it was just a little too small for what I needed. I ended up using my baggallini which I LOVE to this day.
I really like the Kavu bag. And I think the pattern you have posted is my favorite. But....I like the VB backpack too. It's big though...and like you said, backpacks aren't so easy to access at a moment's notice.
I'll be interested to find out what you decide!