Yes Sonys do have a good OTA tuner(it's what I have) and if your area has TVGOS it's much superior to a PSIP guide like on your Zenith/Insignia CECB.
Even though PSIP has the potential to go out many days(I think 7) generally they go out much less, sometimes not even 6hrs and with your Zenith only next/now. TVGOS is always 24hrs and the full blown TVGOS(not on Sony TVs) goes out 8 days.
For a 32" set I wouldn't worry about 720p unless you plan on hooking it up to a computer where you'd need the increased resolution and be sitting only a few feet from the display.
If you live in a smaller market you can check rabbitears.info to see if a station in your area is broadcasting TVGOS.