Almost 2 years update
Well, it looks like this was it for my reservoir- strangely, because I would've expected the water bladder to go first, but it's the blue part of the reservoir that's losing air. It bubbles quite nicely in several spots once inflated.
In addition, the release from the drinking tube doesn't want to come off easily, sometimes at all, from the reservoir. Annoying as hell when I try to pull it out and comes out with the valve- hence water splashing all over (smartened up after couple accidents and keep it upside down when removing the drinking tube to prevent that). Only once it came out on its own while riding, not a big deal cause it was almost empty.
Will see how the lifetime warranty works, I like the system and would like to keep on using this product.
no snowflake ever feels responsible for the avalanche...