After further experimentation with my Ooma, I found that if you put it between the modem and the router as recommended, and you're trying to run a website/do port forwarding/etc, logging in from the rest of the world gets you to the Ooma and not your web server. This rules out doing several things, like MyHouse coverage.
A better arrangement is to hook Ooma into the router, which is hooked into the modem. This allows the router port forwarding to work as desired. What you lose is Ooma's ability to "grab the line." To be honest, though, voice quality has not degraded at all on our 1 Mbps cable internet setup. Can't say how slower DSL will do. I did find that MagicJack service degraded on a DSL line if I tried to do much in the way of downloading at the same time. (DSL is about a third as fast.)
...stuill haven't been able to address my X-10 alarm system dial-out problem (no way to put " *99 " ahead of the phone number). Is there some magic box I could use? ...or maybe buy a separate dialer box and somehow trigger it with the X-10 alarm? (Directly with the alarm, not Active Home Pro.)