Dealerships always push the brand they have a deal with/that brings them the most profit. If you really want honest input from them, go ask one of the actual install techs their opinion on them
As for speeds, im part of the slow puller crowd. 65mph on open road is all i will ever do, I dont see a need to drive fast/rush to get where im going. Its a relaxing camping trip after all
When im on a long haul i usually get in line with an 18wheeler doing about the same speed and let them break wind for me. And quite often i see the same speeding campers going past me 3 or 4 times because they seem to stop more often at the faster rate of travel
