I had the original version of these, which did not have enough heel support for my liking.  The v2 has just a tad more heel cushion, enough to make it feel perfect.

You can wear these barefoot in your standard shoe size, but I dislike doing that- it makes the shoes stink.  I bought these 1/2 size larger than I normally wear, which works out PERFECT with a pair of lightweight socks.

The bottoms are reasonably water resistant, but don't step in any standing puddles more than 1/4-1/2" deep or you will get wet.