Mac OS has virtually no support for capture devices. There's no capture driver standard to speak of and every vendor has their own proprietary driver architecture, none of them tied into the OS features for video acceleration and high quality display.

Of course display wouldn't be a concern with my future setup of having the PVR doing only record and stream duty. But the hardware support is still down to one or two products, none of which I care for.

From some quick research it doesn't appear that there's stable/good/final Linux support for the Hauppauge HD-PVR. This may be the capture solution I move to in the future. It's a choice between that or modified Satellite STB's that allow pulling the digital stream over USB (R5000-HD mod).

Though I may very well switch the OS on which the PVR is built, it will likely be a long time before I give up SageTV, if ever. I'm not 100% happy with some of its UI, but I have no desire to spend time making mods and redesigning that I just live with it and wait around for newer versions to make improvements. The Sage guys thankfully have a better idea of what a PVR and Media player is than a lot of others out there. Obviously not as focused or consistent as TiVo used to be, but still by far the best PC-based setup I've seen.

Their media extender hardware products pretty much seal the deal since no one else has anything like it except Microsoft.