Best OTA TiVO?

I have several TiVos including 3 Premieres (2 & 4 tuners), 1 TiVO Mini, and 2 Series 3 TiVo; a TCD648250B (OLED) and a TCD652160 (160GB drive). All units are lifetimed. I have been slowly phasing out the older Series 3 units in favor of newer equipment, but I am now hearing the Series 3s have the best OTA tuners compared to the newer Premieres and Roamios. I am considering cutting the cord and maybe I should just hang on to these Series 3s. Is it true they are better for antenna use? Or which one is the best for OTA