I've had a TiVo for a long time and a Roamio for about a year and love it. It was expensive and my cable bill is high but I'm good with that and get a lot of use out of it. CNN Money reports Simple, Brilliant and Legal -- TiVo Launches Over-the-Air DVR. I'm not sure why legal is in the headline, they must be comparing it to the Aereo and the Supreme Court case decided a couple of months ago but the article makes no mention of it or any other legal issues.
So the new Roamio OTA can record four shows at once and hold 75 hours of HD programming, pretty nice. Otherwise it's a Roamio, with the great interface, channel guide and integrated streaming services like Netflix and Hulu Plus (of course you have to subscribe to those). The difference is it gets TV the old-fashion way using an antenna (aka OTA). The really attractive thing is, it's only $49.99! At that price it's a steal. I might have made the tuner/storage trade-off a little differently, more storage and less tuners (since OTA has so many fewer channels than cable) but it also works with a TiVo Mini, so you can dedicate a tuner to stream stuff recorded to a different TV in the house.
But there's a downside, like other TiVos the Roamio OTA requires TiVo Service which is $14.99/month. The people I know using OTA TV are doing it because they don't want to pay cable fees. I doubt they're interested in paying $15/month (or $500 for lifetime service). The TiVo really is easy to use and $15/month is a lot less than cable fees so so maybe there's a market for that, but I suspect it will be a big turnoff, as it's been with other TiVo products. Also the TiVo Mini I mentioned is $100 and requires a $6/month service, so I don't know how attractive that is to pair with a $50 device.