I bought the pack as kit for the 3 Peaks Challenge. I have a Deuter 25lt rucksack which has a bladder compartment + hole at the top. The 'Platypus Hoser Hydration System' fitted in well with my set up.
It was easy to fill. It did not leak. It was easy to drink from. There is no mess with this product.
The only negative point I would have for this system is the mouthpiece clip. It is very cheap, and almost looks like an after-thought. Its a shame, as the materials the rest of the kit is made with are very good quality indeed.
Haven't tried cleaning it yet. But then what I am doing is rinsing it out after I have finished with it, wrapping it up and putting it in the freezer. Saves a lot of time that way.