Preserves the lines of the bike while shaving a few grams. Takes some attention to put the bottle back on securely though. Not quite like a conventional bottle cage but I'm getting better at it. I favor the opening of the Camelback Podium but this isn't far off - Better than most. I have these on all of my bikes now and very satisfied. Just bought the tool kettle as well. Very cool.
I use this as the second bottle on my commuter bike. Great for the days I need it, and totally unobtrusive on the bike when I don't. The connection is solid and easy to remove replace, I really dig the system. The bottle however, is not perfect. The hardware cutouts can make the bottle difficult to squeeze, plus the valve is mediocre. But decent build quality overall, and I will definitely continue to use it.
The bottle is the perfect size and shape. However it suffers from being too stiff. It requires focused strength to squeeze the bottle, making it a little difficult to squeeze/drink while riding. The bottle would be perfect if the plastic was made more pliable.