My Experience Installing...

 I have an older Mac - iMac G5 with a 1.8GHz processor. It doesn't have the Intel Duo processor, and I only recently upgraded to 1GB of RAM memory. So I wasn't sure if this product fit my needs - wanted to watch Cable TV on my Mac while Web surfing. The EyeTV Hybrid lets you do that, in about a YouTube sized window. That is adjustable, as well as picture quality and other settings, in the Preferences window. You can also grab the lower corner of the window to manually resize it. Of course, the bigger the window, the grainier the picture quality. The EyeTV 3 software runs smoothly when I am offline, but stutters when loading or scrolling a page on my browser.

A word about setup. I plugged the EyeTV tuner into my Mac and installed the software, but had to restart to get it to work. You will need an antenna or a cable outlet to hook up a coaxial cable to the tuner stick. The other end goes into a USB port (directly into the Mac, not a USB hub). I connected a cable directly to the EyeTV Hybrid - I have a digital cable box on my other TV. Without going through the cable receiver I didn't get all the channels but about the first 100 (Time Warner Digital Basic).

Overall, good but not HTDV quality. I've just started so don't know how well all the features work, or whether the software is solid - it crashed on me once, after installation. I think a faster processor/more memory may be needed to improve the tuner's performance. Also, a 500GB or greater capacity hard disk would probably be good to store video recordings.

If you want to step up the speed and quality without updating your computer, look into the Elgato 10020780 EyeTV 250 Plus Digital/Analog TV Receiver and Video Converter. For an extra $50 you get dedicated processing, thus relieving the load on the computer's processor...but you still need Intel to get the HDTV...I tried one of the 2 HDTV channels the tuner recognized...video quality was much better but halting on my Mac...

Update - 1/19/09 -
     I found the QAM Digital Cable channels, listed by frequency only in Channels  - better picture quality than NTSC, and not so much stuttering when online. But I couldn't find some that I watch on my other TV, and couldn't get them to show up in the Titan TV listings...