There are some non-TiVo DVR options, I think. At least, there used to be. They lacked the convenience of automatic recording of shows, but they also avoided the monthly fees and dial-up connectivity of TiVo type units. Of course, those may have joined hard drive-equipped DVD recorders in oblivion, as I haven't really heard much about them lately.

As for recording quality at higher compression levels, I know that I saw almost no difference between the 1-hour and 2-hour recording modes on my Panasonic, but the 4-hour mode started to introduce visible artifacts that I would not want to watch very much and the 6-hour mode really went down the tubes. It's different from LP and EP on VCR's, as it is a different form of artifact (digital compression looks nothing like the usual quirks of VHS).