I have been using this card for just over a week now, and have the following comments to offer.
I have it in a fairly high spec machine (3.2ghz, 1GB ram, fast hard disks). I am connected to a fairly old roof mounted aerial via a very long (25m) rf lead running through the house. I live in central london, with a decent digital signal, and strong analogue, albeit with some ghosting due to buildings.
On installing the card (with latest drivers off the website), I immediately hit slight problems with errors in the installation, although the errors didn't actually seem to affect the operation of the program.
I have found the quality of the reception of digital channels to be excellent, with a nice picture and good audio. However, quality of analogue reception is frankly poor. Compared with the very old low end Pinnacle card which it replaced, I would say that the treatment of the analogue signal left a picture of about 30% the quality I had before on the same aerial setup.
I found that connecting a cheap booster box from Argos increased the number of digital signals I could recieve significantly, but did not improve the analogue signal.
The software supplied with the card is frankly buggy, and more than a little ugly. I have had numerous crashes with it, and experienced many silly glitches. (Aproximately 30% of the uses i make of it result in a crash of some sort). It feels more like beta software. I recommend instead using software such as Cyberlink's PowerCinema, which is better designed.
In summary then: this card provides excellent digital reception, even on a supposedly non-digital outdoor aerial (no need to spend £120 on an upgrade to that). This is at the expense of poor analogue reception and mediocre supplied software.