My SIL and DD have a non slide Mallard about the same size. Their's has a rear bathroom with tub on the drivers side, a double bed with upper shelf/kids bunk bed, and a big side storage at the back. Queen front bed. It's dry weight is 4300 pounds, so loaded, about 5700.
Your 150 should tow this OK, their Tacoma does. One of the tricks I would use would be to take the slower side roads, and stay off the freeways as much as possible. It is pretty unnerving when you are surrounded by trucks passing you thousands of times. Certainly having a good WD hitch, and knowing the trailer brakes are working perfectly is a good start.
It's not getting up to speed that is the problem, it's managing to stop safely, and make sudden road emergency swerves to avoid something that is the concern.
