The GS is a great bike (as are those in the BWM K-GT line), but the thought of maintaining one is a deal breaker for me. The nearest BMW dealer is 100 miles away and those bikes are designed to almost force owners to the dealer service dept for certain items requiring special tools and equipment.
My plan is to keep the FJR (a '13 Gen 3 model which I love) and add a used Versys 650 to the garage. I do most of my own wrenching, but I've got a Kawi dealer and a Yammi dealer both within 10 minutes of my house if it's something that requires a special tool or knowledge.
Im Lucky I suppose.. within 25 minutes of me, I have Honda, Suzuki, Kawie, Yammie, KTM, Harley, Ducati, Triumph and BMW dealerships.
However for me, it's what is not down the road from me.. Seems you can be in the middle of no where and typically never far from The Big 4 Jap dealerships, and there is Always a Harley dealership as well. I love my KTM, and other than some fueling issues caused by a failing controller that took me 4 months to finally diagnose because it was so intermittent, it has been stone reliable.. However I also know now to take it completely apart and reassemble if the need arises.
Other than my Eliminator, this is the first big 4 bike I have owned in quite some time (street) and I have to say, I do like that feeling that parts and service are readily available should the need arise. Like Most on here I like to do my own wrenching, but I like that security of "just in case."