ATI is still behind NVIDIA for HTPC even with the latest leaked Catalyst 9.6 - It still fails to decode L5.0 / L5.1 high profile AVC video in DXVA mode (using MPC-HC for example). This means that for HTPC, a NVidia 8600GT / 9400GT would be the better choice over ATI HD 4800 / 4700 / 4600 / 4500 / 4300 series.
If you're looking to build a HTPC, go for NVIDIA.
While ATI heavily promotes its HTPC capabilities, the truth is it is still very far behind NVIDIA.
NVIDIAusers have been enjoying this for about 6 months.
@NVIDIA marketing, you could consider starting a "The way it's meant to be watched" program. Doesn't look like ATI has anything left in them to pose a threat whatsoever.