I have them (the regular G5, not the Evo). They are a great all around boot. The fit for me was very similar to the Nepal Evo (same size). The G5s are lighter, warmer, and breathe better. The boa takes some getting used to but I like it much better now, much more adjustable.
FWIW I have never had an issue with water coming in and I've gotten them wet, but it does look like the Evo version of this boot is much better in that regard.