The only OMNI-ANTENNA I have physically played with is the WINEGARD HIDE-AWAY OMNI Antenna. It did not perform very well and also when you was picking up a HDTV station it would start breaking up when aircraft would go passing overhead hehe..
This mounts to side of the trailer and when in travel mode you just pull it down inside the round tube. When it is up you can rotate the twin dipole.
This is probably no better than sitting some old TV rabbit ears on the roof when you park at the camp grounds.
I still have this antenna but it is for a backup...
Along this line you don't have to drill thru the roof to mount a BATWING antenna. I use one associated with my OFF_ROAD POPUP. It is mounted up the side of the POPUP using PVC tubing and Antenna pipe sections. I can setup in just a couple of minutes. I break it all down to transport...
This is what it look likes in my OFF-ROAD POPUP. I can reach thru the window flap and rotate it hehe...
This photo shows me using a LOWES long house HDTV antenna - I now have the BATWING install on top. The $90 LOWES best house YAGI antenna was the best one we ever used but after taking down for one season we finally destroyed the antenna. Broke in half haha... Then we installed the BATWING in its place.
In my opinion our best performance antenna to date is the BATWING with UHF DIPOLE...
Roy Ken