Many thanks to all (esp. Gerard from sodaclub) who replied with feedback and advice. After almost 2 weeks, I'd say sodaclub has been an almost unqualified hit. It really is easy to set up and I like that I can control the carbonation. The seltzers have turned out perfect. I originally got it for the seltzer, but the soda samples in the kit have turned out to be really surprisingly good. We've gone through 4 flavors so far, with the cola especially notable. Not too sweet, and lighter than regular Coke.
My only (little) quibble so far is that sometimes an entire bottle will stay carbonated to the last drop, but sometimes not. It also looks like I may have an issue with a defective cap, but sodaclub has been prompt in dealing with it (I hope). I also wish that their enclosed DVD/CD had a video demonstration of how to first set it up, rather than a graphical demo, which still left us with a couple of questions (this last one is for you Gerard).
I would recommend it highly (and have done so to my fellow seltzer drinkers at work).