It's a water container...
The appeal is the light weight, small pack size and the large volume. And all of these things are very true. Mine weighs 1.3 oz empty and packs down smaller than any of my other water containers, and even though it says 2L, it will actually hold more than that.
However, I will have to keep an eye on the durability of the actual "bottle". I currently own some of the Nalgene Cantene's and IMO, the Nalgenes are a little more rugged and durable. I have used the Platy on one Backpacking trip in which I carried the bottle rolled up inside my bag and only got it out at camp to haul/store water. When I arrived back home, I noticed some dents and scratched looking spots on the bottle. This is ok for now, but it makes me wonder how it will do in the long run. In comparison, my Nalgene has been used many times in the field and has held up well and is fine.
Also, as expected, filling this thing is work, due to the small opening. In comparison here as well, the Nalgene's wide mouth is awesome. I tried filling this bladder in a deep stream with fairly fast moving water and it took a few minutes. I had to completely submerge the bottle a few times, and of course I ended up with cold hands. I would hate to imagine trying to fill this from a shallow water source...
So, at this point I am just curious as to how it will hold up on multiple trips. it will be in my pack on trips in which I know there are very reliable sources, at least for a while.