A few years back a riding buddy/co-worker and I rented an RT and a K1200RS for a ride to Tahoe from BMW of San Francisco (they no longer rent bikes). Of the approx 1200 miles on the trip, I rode the RT about 400 miles. To me it was like a 5 or 7 series, the K1200RS was the M3.
The K1200LT has the same I4 as the K1200RS, I think it may be tuned slightly differently. That engine was smooth and quiet, but was incredibly responsive. One of the things that contributes to "numb ass" after a long ride is engine vibration. It was non-existent. After that ride I was ready to buy a K1200RS, but I got hooked on the Autocross thing, so my mad money goes there instead. Still, sometime in the future, I see a beemer K bike in the garage.
Beemers hold their resale value really well, so that also works in your favor if you want to sell it in a few years, or trade up.