visiontek HD 650 pci express tv tuner

hi everyone,
I just recently purchased this item, my first tv tuner. It works great, but I have several questions that I am hoping you guys will be able to help me with.

1. I currently use the bundled ATI media center software. It's ok, but it's slower then I like, and crashes too frequently. Are there any good alternatives that will allow me to use the full capabilities of this tuner?

2. I like windows media center (WMC) that came with vista 64 ultimate edition, but I've heard I can't receive QAM channels. for that matter, I can't receive them using ATI MC either. am I doing something wrong? How can I view QAM digital channels on my PC?
*** I am assuming that I DO NOT need a set top box to receive QAM, correct?? I should be able to receive QAM directly through my coax cable that's coming from the wall?? Is there some kind of service I need to sign up for in order to receive QAM channels, I thought the local ones were free...

My PC has vista ultimate 64, an HD 3870 vid card, E2160 overclocked to 2.8Ghz, Abit IP35-E motherboard... not sure if you need other information but feel free to ask!

Oh and I am a comcast subscriber (digital classic service package/non-HD) located in the NW suburbs of illinois (chicago land area)

Rick,
thanks for the link you provided! although it gave me bad news (no QAM support in WMC, without a certified OEM digital tuner PC), it also provided me with some valuable information that pointed me in the right direction for other questions that I had.

thanks again.