My opinion is most, myself included, would not recomend tilting because most wont get up on the roof to utilize. I copied the 4 way tilit mounts to maximize potential and have the option. Though it can easily double output it does get old. By tilting I can go from say 0.2-0.3 amps to 2 or 3amps, can extend charge times following the sun. But its an option. Whether needed or not I have it. Most would be best served when flat mounting-insureing no shadowing by vents, AC etc. If I ever mount an addtional panle it probably wont have tilt option.
Our camper is stored and use a cover-its 11:30am and solar probably has already reached float stage.