I've been on the PVR bandwagon for a while. I originally owned a Panasonic ShowStopper (ReplayTV) which IMO is more powerful than the Tivo. I have upgraded that unit to 80 hours and it has served me well for over a year.

Recently, though, I also picked up a DirectTivo mainly because of the dual tuners. I like being able to record one thing while watching another. I promptly upgraded the DTivo with a 120GB hard drive (109 hours) and so far it's been great. The Tivo interface is a little dumbed down for me but the wife likes it.

Far as the serial port, yes, the DTivo does have a serial port. It's on the back and is labeled SERIAL. In place of the standard serial port, however, they used a headphone jack. You can make a serial cable for the unit with about $5.00 worth of stuff from Radio Shack. However, you can't get shell access without hacking the unit. I had my unit hacked but later decided to just leave it alone and put it back to "normal."

It's amazing how quickly you get used to have a PVR. With my Showstopper and the DTivo combined, I can now record 3 things at once at any time and believe it or not, that happens a lot.