Most people don't venture into this territory of large bags but it's incredibly useful. Spare 29er tube, multitool, pump, phone and wallet with room for hat, gloves, shell; no problem. Quality is unparalleled, I can't imagine ever wearing it out. All worth the extra dollars for USA made.
Two unsecured pockets on either side. No pockets inside, just a cavernous interior. In addition to the bar straps, I use the daisy chain on front to lash to my Jones H bar so it's secured between the fore and aft bars. You'll more likely use the daisy chain to strap something outside the bag.
Has plastic stiffener to keep the 'burrito' shape. Zipper is supposed to be waterproof so expect it to be hard to open for awhile like mine. Seems to be getting better with use.