I'd be hesitant to say Camelbaks are more durable than Platypuses. I tried a 2L Camelbak for cycling and backpacking a few years back, and I really liked having a reservoir on the bike for hands-free hydration. However, within one season I blew through two bite valves, and then started having problems with leaky seams on the reservoir itself (not the plastic ridges in the cap, but in the rubber body).
Instead of replacing the whole thing, I just went back to using recycled 1L bottles and Platys, which are way more convenient for hiking, and lighter. The Camelbak is also quite hard to fill at streams, especially if you pump your water, because there is no way to stand it up. With a Platypus, once you get an inch or two of water in the bottom, it'll stand more or less on its own. Also, for $10 (or maybe a little more now) you can get a hydration hose to fit a Platy softbottle--I've ended up with one of those for bike trips, but when I'm hiking I usually leave it at home to save that tiny bit of weight. Bottom line is, find a pack with easily accessible bottle holsters, or fashion a bungee system and loop your bottles onto the shoulder straps (ala ULA packs). Good for the weight distribution.