It took a little while to get everything setup and working, but my ooma service is now fully operational (including phone service changes, which I'm still unclear about).
The hub is bigger than I expected but feels very solid in construction.
Call quality so far has been quite good, but there is a faint "buzz" in the background that isn't there if I bypass the hub and connect directly to the phone line.
The voicemail is pretty cool, but I wish I could get the messages as an attachment in email. ooma lacks some of the features I had with Vonage, such as ringing several phones when people call. I also miss the softphone feature. But it's nice not to have monthly fees!
I've seen some people complain about the little "ooma tone" that both parties hear on all calls, but I'm not bothered by it, and so far nobody I've called has been either.