Long story short. I recently swapped my 2013 Guzzi 1400 California for a 2017 model R1200R sport. I also have a V85TT Guzzi. What can I say, it's been a bit of a revelation for me. I wasn't looking at a 1200r, but it was on my list of possible swaps and the deal on the California was a very good deal.
I expected it to be a bit like a lower version of a GS, but it's so much more, slightly lighter, slightly quicker, and a whole bunch more fun to ride. Mine came with a low seat and even though I've only a 29" inside leg it was still a little cramped. I've now sourced a standard height seat and it's great. My feet are almost flat on the ground and legs are at a nice angle when on the pegs. I've also added a screen and handguards, which whilst detract slightly from the look of the bike, serve a useful purpose.
When I purchased the also had an R1200RS, which was very nice, but just a little to far forward for me, the R has a much more neutral seating position, having said that, I am 65.
The R1200R is an absolute belting bike, riding position is great, it's not as cumbersome as a GS, it handles really nicely and is fairly easy to manhandle. As for the 'Quickshifter', yes it's good and particularly nice when needing to drop a gear or two at speed. I find that you have to put a whole lot more pressure on the lever for up changes, whereas if you use the clutch changes are super slick. Having said that, once in second gear and accelerating hard, the thing fair fly's upto fairly rapid speeds when using the quickshifter.
Overall it's a very nice bike and maybe somewhat overlooked. I suspect that, if many prospective GS purchasers tried the 1200r before purchasing the GS, there would be a fair few go for the R, it's just a much more engaging bike.