I finally got the chance to give my reservoir a try, and it's great! There are couple of features that make the hydrapak reservoirs really nice.
Detachable drinking tube! - The detachable drinking tube is a really nice feature, especially when used with my pack, which routes the drinking tube through the shoulder strap. This allows me to easly remove and refill the reservoir without having to deal with fishing the tube through my shoulder strap again.
On/Off bite valve - You can twist the bite valve to positively shut off the flow. If you've ever had your hydration pack leak all over your car or gear, you know how valuable this feature is!
Reversible - The top of the reservoir open up and allows you to flip them inside out for cleaning. Watch this video
Strong! - I think this video says it all!
If it's time for a replacement reservoir, or you're in the market for a new hydration pack, I'd highly recommend a look these Hydrapak Reservoirs. I didn't see any Hydrapak gear at my local sporting goods stores, but I did find serveral partner branded hydration packs with clearly labeled hydrapak reservoirs. Of course Amazon has a full line of Hydrapak reservoirs and parts