I was fired up to get a new Tivo for my OTA viewing but found out that Tivo does not support secondary markets. I watch OTA from Austin and San Antonio.
For OTA I prefer non-subscription units. I have a Channel Master CM-7000PAL (despite the branding, it was actually built by Echostar, the Dish Network spinoff), but those aren't made anymore and are hard to find.
Has anyone tried the Magnavox MDR513 or 515? They appear to be combination DVRs/DVD recorders. From what I've read they're OK except for one drawback: unlike my Channel Master they can't record in High Def. (even to the internal hard drive

).
But if that's not important in your case (if, say, you want to record SD shows anyhow), they might be worth a look. At a minimum you could use the TiVo for primary market stations and the Magnavox for secondary market stations.