There is actually a chart online with the differences, see:

HD TiVo Comparison

The Series3 THX version is built with better materials and is really a higher-end unit. After the $200 rebate special, it is a pretty compelling box to purchase...but if you aren't looking to put it in a high-end home theater, then the lower-end box is likely to be just fine.

Not to be rude...I did see the chart when I was shopping at your site, but hoped for a more concise distinction on the differences. Are the better materials worth the $100 more? I don't have a home theater set-up now, but will probably do that in the future...though I might go through a separate receiver anyway, so does it make sense to get the higher-priced unit?

And what about the wireless adapter question?

Thanks...

A E

The TiVo adapter is preferred; there are other compatible wireless adapters out there, but finding one can be tough. Also, the TiVo-branded is far better.

We really cannot make the personal choice for you on the TiVoHD vs the Series3. However, as I said, with a $200 rebate, it sure make the Series3 a compelling choice. If it were me, I'd go with the Series3 with the $200 rebate. Better materials, better remote (alone worth $49), LED display, THX-certification.

Regarding your wireless question, I believe that if it works on a series 2 it will work on the HD and series 3.

Regarding differences between HD and Series3:

http://tivosupport2.instancy.com/Lau...5-4BFDE6A851E4 describes how dual-tuner cableCARDS are supported by Tivo HD, and not supported by Series 3.
This is another difference between the two (and adds a potential advantage to the "Cheap" one!)

Also note that the HD has 20 hrs, S3 has 30 hours. If you upgrade the HD to 30 hrs, the price of the 2 units is exceptionally close. (This difference was failed to be highlighted in bold on the differences page). 20 hours is very little. Of course, the cheapest way to upgrade space is to add 500 gig using the external drive for $200 from Western Digital.
Also S3 has THX certification, but no idea what that may actually mean to the user (more accurate sound/video reproduction?)

As far as I know, the TiVo-brand adapter is the only one that works with the Series3 and TiVoHD. A wireless bridge may work of the ethernet port, but nothing else would work off the USB port.

Weaknees might want to update this grid. You can now transfer video OFF of your Series 3. I have a Toshiba Series 2 and a Series 3, and I can transfer video between them now... but only the standard-definition stuff, of course.

I think this was part of the fall software update.

Good call - working on it!