I have the same card - providing you get around 70 per cent signal strength and quality in the 90s pictures and sound are fine.
The PowerCinema drivers and software that orignally came with the card was a stop gap until Twinhan produced and refined its own versions.
If you go to click here and download the Hybrid 2.611a software and the latest (VP-3504) BDA drivers (there's a choice of 126.96.36.199 WHQL certified or "Latest" with the same version number), it's easy to set up.
Install the drivers first and then the software. Once this has been done - you will have to reboot at least three times!) - you open the Control Panel of the software and click on the small grenn section on the left to open a panel.
Second from right (top level) is the Configuration button. For the first open the second tab, check the boxes from around channel 23 onwards, and then go to the first tab (Easy setup).
Select Country Scan (UK 44) and also the Analogue box (if you want analogue TV stations as well) and then let the software do the scan.
Once this has been done and OK'd open the Favourites panel, where all the Freeview TV and radio stations will be listed (also in the second tab from the Configuration button).
Some may be duplicated - due to some stations switching at certain times such as BBC3 and 4 with the Children's Channels).
On the Control Panel (bottom right button) there's a video adjustment section. I find that just the brightness setting needs increasing slightly to prevent too dark a display).
You'll also find a Help section is available if you get lost...:-)