TiVo TCD649080 Series 2 80-Hour Dual Tuner Digital Video Recorder (2008 Model)
Change the Way You Watch TV
I upgraded to the 80 hr duel tuner from a 40 hr single tuner.  The change was mainly since tivo's now have a small initial cost ( there's usually a tivo rebate available ), so I might as well get the the extra space and the extra tuner.    The upgrade was very noticeable; almost immediately I wondered how I ever got by with just the single tuner.  During prime time I would often have to miss one show in order to record another, that problem is now solved.  Additionaly being able to watch something else while the tivo records just adds to the control you have over when you watch something.    I now have the old tivo in my bedroom, connected wirelessly to the new one.  I'm able to watch something off of the dual tuner on the single tuner as its transfering, however it isn't fast enough to be able to fast forward more than a couple minutes, so you're going to get the commercials in that case.  Not a big deal, and not tivo's fault.  Occasionally I have to unplug and replug in the wireless transmitter ( purchased seperately ) to get a higher transfer rate, but I'm not certain if that is the tivo or adapters fault.