Tiro's DVR just works and is mostly rock solid. You just need to decide whether you want to pay the lifetime subscription fee up front or go month-to-month for $15/month. I chose a month to month subscription because I seem to change my system every few years. I'm going on nearly 2 years with my current Tivo and it has been fine.
Remember that you need the Tivo that supports OTA. Not all models do. Also consider getting the Tivo Stream if you want to watch live or recorded tv on your mobile devices.