I installed a Zenith in the motorhome, and it works great. It has a feature called 'pass-thru'. That means if the converter is off, the antenna (or cable, as the case may be) is fed through the converter to the TV. So if you are at a marina that has cable, you don't need to disconnect cables to bypass the converter, or install any "A/B" switches. It done automatically.
The Zenith has picked up many more on-the-air digital signals than I would have expected, with the same old batwing antenna.