Just me, but I don't see any particular advantage to an RV specific GPS. If you have a smartphone, between the two you'll cover pretty much any info you desire. As far as clearance issues, probably not an issue with your TT, OP. I previously owned a fifth wheel that was 13' 6" at the bedroom AC and never had a problem with bridges. OTOH, low trees extending over the highway were a constant concern and sure weren't in any GPS database.