Seconded. One thing to consider is, drivers and applications delivered with standalone TV cards tend to stink severely, both in quality and use. The software ATi ships with their AIW cards is a true relief in comparison.
Technically, the win with the AIWs is that the TV capture data do not load the system busses at all - while viewing, the stream directly goes from capture chip into overlay RAM onto the same card, while with a PCI TV card the stream has to travel up the PCI bus and inter-chipset link onto the AGP port to finally reach the overlay buffer inside the graphics card RAM.