The new entry level Tivo Roamio does either OTA or cableCARD. 4 tuners.
The next models up have more hard drive space, built-in streaming capability (requires an add-on for the entry level unit), 6 tuners, and require cableCARD. No OTA. The only difference between the two upper models is hard drive space.
I've had 4 tuners for a few years now; I can live with that. Were I going Tivo, I'd happily trade off those two extra tuners in exchange for having OTA capability if I wanted to switch to that (very much a possibility). As for hard drive space, that's always upgradeable.
Back in the day, three lifetime Replays was how much? $1500? You had three separate recording tanks--no unified recording schedule--and streaming between rooms. Nowadays a three room lifetime Tivo setup with 4 tuners and unified recording schedule is, um, $1200. Plus tax and maybe some remotes and extended warranty, call it the same $1500. It's impressive that 10 years later the cost hasn't gone up while a bunch of the technology has improved (multiple cableCARD tuners, streaming to remote devices, etc).
At the same time, it's sad that 10 years later a bunch of superior Replay technology got dumped in the trash can, and the only way to get it back is to roll your own DVR (Myth, WMC, etc).