A beta / DVT H2O magically appeared on my desk and I've been using it in place of my Aura (another beta / DVT unit), and I'm impressed with it. I'm not sure how close to final either of the units I have were / are, moreso the Aura, but the H2O does seem to have a much brighter screen, I don't mean the backlight, I mean just the page itself seems brighter. It, obviously, is crisper, due to the HD nature of the display, so I'm not sure if that also accounts for the aforementioned brightness.
It's bigger than the Aura (duh!) and it took me 10 minutes to get used to the difference in size, but it feels normal now. Pages turns seem quicker than the Aura, though I've not timed them.
I have not tried the waterproof side of life yet, but will get round to it, probably take it in the shower. Proof of that won't be forthcoming though, for some obvious reasons
but also because I don't have another waterproof device to show it being used in the shower, nor do I have multiple extra arms and hands to hold various things!
Feel free to take what I say with a pinch of salt, but I'm happy with the device, and yes, even if I hadn't had one appear, I honestly, hand on heart, would have purchased one, and I'd still have been happy.