I have a Lava OmniPro HD-8008 and love it. Have it laying in the cab over and it does fair. Have piece of aluminum conduit that I can attach it to that is clamped to the ladder then it does excellent. Can set this up in under 5 minutes and no aiming required. Have been able to pull in stations that the standard bat wing RV antennas wont.
HD-8008 link