I've used the Marvel G400-TV since 2 years. Works great.
Dual head= Computer monitor + TV out.
Hardware MJPEG codec, unfortunatelly Matrox stopped developing HW MJPEG drivers but software codecs like PIC Video or Morgan MJPEG codecs have higher quality (you need faster CPU for them)
You can't play Matrox coded MJPEG .AVIs on other video cards.
Matrox has a built in Macrovision protection. It's an issue. You may use some Macrovision crack. You can watch DVD on TV, but can't record it on VHS.
So, the G450-TV is similar, but I never tested it. Just satisfied with Marvel G400.
For DV you may look for Matrox RT2500.
The choice between Marvel G450 and ATI? I'd go Matrox, anyway.
greenpoint