I've been wearing my new Keens for a little over a month now. They are doing everything I wanted them to do. They have good arch support, are actually waterproof, and quite comfortable.
Tongue-Yes, the seam in the tongue did cause a few issues. It doesn't feel lumpy but the seam between the waterproof fabric and the regular fabric on the tongue does press against the top of your foot the first couple of times. Having been warned, I tied them a little loose the first couple of times and only wore them for shorter periods of time before testing them all day. I didn't have any problems with the tongue after about a week and a half.
Waterproof-Yes, the shoes are waterproof. I tested that out last week when I rode my bike home in the rain. My feet were staying completely dry until I rode through a puddle deeper than I thought. I splashed water up and got my socks all wet. The water from my socks eventually wicked down to make my feet wet but it wasn't do to the shoes. Guess I need waterproof socks now...