I have never had any type malfunction with the Camelbak and has served it's purpose quite well.
The 3L is good for short missions or cool days. Because the reservoir is shy of 1 gallon of water, you will definitely want to take more water or know of potable water sources along your route if you are looking to be out for a long period of time or on an extremely hot day.
They make larger systems, so make sure you buy in relation to what you will be using it for.
Believe it or not, water can get real heavy real quick!
Pros: Ease of use and transportation in the field.
Cons: I haven't found one yet.
This review was written in the old system and had content requirements that are different than reviews written today.