Jensen it is... In my experience, any of the "omni directional" antennas are going to be less effective than a directional and they are even worse not being on a pole since they are closer to the trailer's roof and roof clutter.
The best antennas are going to be higher (height is your friend) and well away from the roof clutter (rotating electrical masses; A/C, roof vents, etc) make for lousy signal reception.
How easy the change-over to a crank up antenna is dependent on your year and model as to where they placed the omni directional antenna;i.e., do you have enough room on the roof for a fold down antenna arm, is the crank assembly going to be accessible inside, etc.
IMHO, the best antenna setup that I've run (and am currently running) is Winegard antenna arms/crank and amplifier with a Jack Off the Air amplified antenna. Basically the Winegard Sensar with the Sensar thrown out and a Jack installed.
Even the best antennas though are only as good as the television they are attached to. My Cougar came with a 32" Sansui...piece of junk. The tuner in it is very weak...I have a second television in the bedroom, a Vizio that I bought and installed. While in Butte, MT, two weeks ago, with the area on fire (literally) there was so much smoke that the Sansui could only find 2 stations and they were pixelating as much as they were clear. Turned on the Vizio in the bedroom to find 8, rock steady stations being received without changing a thing on the antenna. Needless to say the Sansui will soon be "history" and a new Vizio is going up in its place