Thanks for the responses. Based on questions from above, the tires are 27.5+/2.8". I rode 13 miles today (first actual ride other than dealer test rides) at 26 psi front and back and will experiment by adding and subtracting 1 or 2 psi every ride or so until I'm 100% comfortable. Next ride will be 24 psi front.
It was a mental thing with me. As a road rider, it's strange looking down and seeing 2.8" knobbies. It's also very strange going from 120 psi to a psi in the twenties. Now that I have confidence that I'm not going to pinch flat and that these tires will roll over most anything, I'm pretty much set to go. BTW...Today's ride was a blast.