[ZetaVu]

The HD PVR is a hardware encoder to H.264. A 1hr recording on typical settings is about 3-4GB, which makes it about the same size as OTA HD recordings and only slightly larger than mpeg recordings. Of course you need to make sure your machine can handle the H.264 recordings, you need the equivalent of an 8500 (nvidia) or better to hardware accelerate (not sure about the ATI spec) and many people have had issues adapting. I'm using it without issue on my Directv H20.

Otherwise, for SD recording you can go with the Hauppauge HVR 1800 (single) or 2250 (Dual) tuners. Both are PCIe 2x and hardware encode svideo or analog signals as mpegs. I have an HVR 2250 but use it for OTA HD. You can also capture QAM or use the svideo output of a STB to record. I've had my best luck with Directv boxes using a serial port cable (null modem cable attached to an iogear GUC232A serial to usb) for tuning, I use the setting Satellite box 2 in setup.

Good luck.