I have had concerns with bladder bursts (no, I don't want to be a baby...most of the time) but thankfully have never had an issue. I also just bought the Switch 25+5 pack from Osprey (last year's model), and they have a pretty nifty way of getting around the burst issue. It's actually two packs in one, with the bladder in a totally separate lightweight bladder pack, that is independent of the main compartments of the pack. Sure, it's probably not the most lightweight way to go (although I haven't really noticed the weight). Oh, and one of the pack straps also acts as a bladder hose insulator so you don't get the hose-freeze thing in cold conditions. The pack is also extremely well-organized and fits what seems like a ton of stuff for its size. It's billed as a backcountry ski/snowboard pack, but it's great for light alpine stuff, too. And, if you want to use it for trail running or a super-light adventure, you can just pull the bladder pack out. It holds up to a 3-liter bladder, which is great. I always pack at least an extra Nalgene anyway, but I love being able to hydrate without stopping. Anyway, if you couldn't tell already, I'm a big fan.