I have an Elgato eyeTV Hybrid that I use for over the air HD recording. I have used the EyeTV software to cut sequences and save the result to QuickTime files of a smaller size. Works great and the editing is easy enough, although I can't see that it would be any easier than a Windows alternative, unless Windows alternatives are really that bad. Editing can be a little time consuming, so things you are just going to watch once and delete probably aren't worth that time. I certainly don't waste my time editing time shifted content.
The Hybrid streams the HD signal straight into a file but I'm not sure how it is encapsulated. So you'd want to test if your WinPC could read the file directly with appropriate software. Things I want to play via iTunes and QuickTime I have the software convert automatically sometimes. Oh, the analog recordings are fine from cable, but not so great over the air, and this box also does not have an analog-to-mpg2 encoder so my Mac does that process. Some tuners can do that.
I haven't timed it, but an hour of 1080i TV takes more than an hour on my MBP laptop to convert to a QuickTime file. On my older Dual 867Mhz G4 it takes about 4.5 hours, if I recall right. The setting I use is "Best - 640x480 H.264".
Streaming over a network should work fine if it is 100Mbps or better. I think I had issues with wireless-G and decided to copy files first. YMMV. Gee, six months seems soo loong ago. My experience is with Mpeg2 files recorded via an ATI analog tuner on a Win2K box. I don't have that information handy and can't recall how large those files were. The smaller the file for the length of the content, the more likely it will work without issues.
Although I think the media server thing is promissing, I haven't bought into yet. File format issues, software issues, and the cost of running a server 24/7, which I have done in the past, are a bit gross right now. Also, I keep in the back of my mind that digital broadcasting has the no-record bit capability ready to ruin any time shifters day. I expect that to kick-in in 2009 when analog is scheduled to disappear in the States. Maybe the industry will offer a somewhat user friendly DRM'd recording capability, but don't be surprised to have to buy new hardware and software and pay dearly for it, and it won't be available for the Mac right a way either.
