I have a PS3 and an HR21 DirecTV HD-DVR.

I am assuming the following would be the best setup:

HR21 set to output in native resolution, let HC4900 covert to 1080p.

PS3 set to output 1080p always (will covert SD-DVD and PS2 games to 1080p), HC4900 does not conversion.

Is this the optimal setup?