So I wanted to share my first impressions while the reaction is still raw. This is going to sound like the worst kind of low-level whining about minor issues, and I need to keep in mind I've had a steady diet of Bavarian cool-aid for 6 years. And the most exclusive flavor, mind you, the ABS/Robo-brake vintage. Time and/or farkling will most likely fix all my issues.
The switch gear sucks. As I write this I still don't know how to reset the trip meter. No self-cancelling signals, so I'll be Snow-birding it up and down 287 for a while. Rdsmith3, please smack me when you ride pass, or hit my cancel switch. How this stupid business of having Left, Right and Cancel all on the same switch became the world standard is beyond me. Anyone who thinks the BMW system (up until this model year) is wrong is... well I'll be polite and say that they're wrong.

I'm fine with the horn button being out of the way. I believe that if you are relying on the horn to keep you safe, you are a complete failure as a motorcycle rider.

There's this weird delay when shifting into neutral and the green "N" coming on.
Whatever the clever folks in Spandau do to make sure you don't overflow the fuel tank, it's missing here. While trying to correct the first thing I was kvetching about, I suddenly start to feel some liquid drip on my boots. A lot of it.

The meticulously maintained motorcycle from the previous owner is now completely covered in gasoline.

At least there's no hot jug sticking out to light everything up in flames.
The grips are too small, my right hand cramps up in 10 minutes. The cramps leave and come back. My legs, unused to this new riding position, cramp up in 5, but that goes away as well. The leg room is not nearly what you get in a GS. The smaller, aftermarket windscreen is much better than stock, but it's coming off before my next ride.
The transmission is smoother than the R's. However, on the highway ride home, I caught a false neutral, and it kicked itself back into gear in a most alarming fashion. I swear I heard metal tinkling inside the case. Great, another gear box with issues.

Oh, and a chain to lube at the end of the week.
The brakes scare the crap out of me. The whizzy brakes are touchy... and I like them that way, on the rare occasion that I actually need them. The engine braking on my bike practically throws me over the bars by chopping the throttle, so at 33K miles, the pads barely look worn. That's all missing here, however...
The motor, as Bobw pointed out, is beyond reproach. Smooth throughout the rev range, I have to find another way to figure out whether I'm doing 60 or 95. The throttle is wired right to my brain, rather than a call down to the engine room. And today was a good day to expose another positive feature for this time of year: liquid cooling. I had about 10 minutes of stop and go riding, and it was nice not to have to worry about how the oil was holding up.
And the whole thing is just a bit more than 1/2 the price of the used R1200GS I was thinking about.
So that's about it for my geezerly grumping. If the proverbial gun to the head was asking which bike goes, it would be the Tiger... for now. But Grip Puppies, Tall Seat, Buell Pegs and Kisan signal minder, and this could be the ride for me. I will be switching between the bikes for at least a few weeks, and give it a chance to grow on me.