Yes ATI (with the proprietary fglrx drivers) works reasonably well as long as you don't need mpeg2 hardware decoding and don't need h.264 > L4.1 or any advanced deinterlacing.
Basically the ATI XvBA hardware decoding is currently limited to VC1 and H.264
Basically the ATI XvBA hardware decoding is currently limited to VC1 and H.264