As for the 1200RT it is clear you haven't ridden one and know bugger all about them.
Your right there, it is only from looking at them, they appear dated and heavy and the engine is light years behind modern engines, even other Adventure bikes really show up the weakness of the engine, the Super Tenere is far smoother and just as quick, the Tiger 1050 is more powerful and smoother and the MTS lump is just leagues ahead.
I paid £7900 for my ZZR1400, by the time I reworked the suspension (Including Ohlins shock) added hard luggage, reworked the seat, Autocom, fitted risers and a taller screen it still stood me in at under ten grand (I suppose at today's prices this would be about £11.5k)
I know you could argue it ain't a tourer, but it was a bloody fast bike with unlimited grunt, dead smooth motor, handling only a smidge off that of a full on supersports bike and with a 200 mile range.
I would not fancy a FJR, but I would
assume them to be superior to the RT in handling, and I know the engine is far more powerful and much smoother and I would guess the comfort similar.
All of these behemoths (FJR's / PAN's etc) are not my cuppa tea at all as although they would wisk me to the Alps in comfort I suspect I would not want to ride them through bends all day long once I got there.
Maybe when I am too old to enjoy corners anymore and just want to look at the views I will buy one - but a car will do that job as well and with even better weather protection.
My current thinking on a tourer (and current thinking changes with age, hence the ZZR is no longer a tourer in my mind) would be alonmg the lines of a large faired bike like the Suzuki 1250
http://www.suzuki-gb.co.uk/bike/gsx1250fal0st/
These can be had with luggage for under £7750 (and at 0% finance) I would Ohlins it up and get the forks reworked at which point the handling would be pretty awesome and with the £4k I have saved over the RT I would book up a load of Alpine Hotels and go have some fun!
In the Alps last year I met a chap on an earlier version, he had covered 82k on the thing and apart from routine servicing he had nothing done until 78k when it needed a wheel bearing just before this latest trip.
If it was not that locally I ride a lot of unclassified roads and like the ability to take to unpaved roads in places like the Alps I would probably be looking to buy something like that.