I am so happy with my Spin Bag 18L that I bought last summer. I use it everyday at work but have also been taking it kayaking and canoeing, it's perfect for water sports because it's waterproof :) But mainly love the ergonomics, it's just perfect!
I purchased both size bags and found them far more durable than any product. Years of traveling checked at airports, hiking, bike touring!!! After almost a year and a serious bicycle accident I had a small hole where most materials would she'd against the pavement. I patched it with a tough reflective sticker and it's as good as new. All I know is that it's the only back packs I'll ever need, recommend and ever purchase again.