1. Overall I like the bag very much, I'd probably give it 4 out of 5. My only complaint is the strap. The padded part doesn't really sit where I need it.

2. No, if you want something to walk with buy a backpack. Messenger bags only have one strap, which is fine when you're leaned over on a bike, but is never going to be comfortable when you're walking long distances with any sort of weight.

3. I've gone on 50+ mile rides with it, and it always sits just right on my back. While I'm watching my friends move and adjust their chromes and timbuk2s the pac is comfortable and stable under any sort of riding condition. Plus I've never not been able to fit everything I need in/on it, including entire bicycles, which stay put while I'm riding.

4. If you use it every day, and you never need another bag, then sure.

5. I've had mine about 4 years, the velcro that holds the flap down is sort of coming off the flap, but it isn't really needed to keep stuff in the bag, and if I'm carrying a lot I just use the straps.

6. The main buckle is holding up fine.

I have the street scene large.