Mark, I am just voicing my opinion. Just like everyone else here. I have had your bike, an LT and even an F650. So I have traversed the BMW product line (just not boxers, I cannot wrap my head around them, and no, that is not trolling!). The GT to me is an S or an R with a larger fairing, and for my bucks, I would get another LT. Which as it happens, I am doing next spring. The missus really liked that bike and I will be in the market for a used one.
So my point on the GT is, is the fairing, hard cases and some gadgets worth the 5-7k more? It is up to the individual to decide.
Speaking of the missus, she liked the RS better than the R. For a pillion it is a much more comfortable ride, as the seat is better and less sloped forward.