Actually, I also switched from a DirecTivo unit (2.5 years user) to HD cable.
My reason: I moved to a wooded area and satellite was problematic to setup (for HD capability, I would have needed 3 poles and cut 5-8 trees, >$1000 setup) . So I relunctantly called Comcast, but I setup my HTPC with SnapStream software for my PVR solution, which in my opinion doesn't necessarilly have all the bells and whistles that Tivo software has, but defintely has a simple and attractive UI and it's $69 MSRP with no monthly fees! After getting used to it, I'm pretty happy with it.
I even gave ReplayTV a shot, but returned it within 48 hours. I've read that Tivo users can't get used to ReplayTV and vice-versa, and that's what my personal experience was. Also, I definitely didn't like the 5+ seconds lag between cable channels... though I heard my unit was probably defective.
Dave: while you were lucky to take advantage of the lifetime subscription, it's not available anymore for DirecTivo units and it's now $299 for standalones! Is it true that if you upgrade (for example to the HD DirecTivo), you won't be able to transfer your subscription? I heard about that, and it scared me out of the lifetime subscription.
Also, what annoys me the most about owning a PVR is what 3 of my close friends experienced recently (two standalone Tivos and a ReplayTV). The harddrive of their unit died in just a little bit more than 2 years of usage. Not only they lost all their recorded programs, but had to pay major fees to get it fixed. While this is not a typical experience from what I know, the bottom line of this issue is that harddrives are not meant to be used 24/7 non-stop for years and will get more defects and eventually fail after a few years. While renting the unit won't be problem-free, it will aleviate the costs of replacement if you used the unit appropriately and the harddrive fails on you.
Finally, I don't know if somebody saw any HD PVR box with two tuners recording at the same time while playing back a pre-recorded show, but that sure seems impossible to me with the current technology. High-Def takes a large amount of bandwidth to record, multiply that by 2 (including the seeking times) and then add the decompression cycles and seeking time on the harddrive to read the 3rd steam for playback and that feels like frames will drop. Anybody saw that working?
Anyways, I just wanted to give my experience and opinions on the near-future solutions. And I hope both HD-DirecTivo and Mot 6208 will exceed all our expectations!