I had a regular Multi. (04 model) used for 6,000 Miles (10,000 KM.)
I liked it a lot.
Then came a couple of "S" models to the dealership, One Black, One Red, traded it in for the Red one and a friend of mine traded his, for the Black one.

After the first ride (180 Miles) we could not believe the ...

I also have a FZ-1 (Fazer 1000) in my harem.

What I dont like of it, is that my legs are very cramped (34"Inseam)

The Multi has the best seating position of the 3 bikes you quote, the
"S" model has a VERY good seat compared to the first models (04),
much wider mirror stems, HD handlebar, and the ...

If you try the "S" model, you'll find out that Ohlins are everything on this bike and make a tremendous difference compared to the regular Multi.

It even seems like another bike (a much better one of course)

Check this one for the V-STROM

http://www.vstrom.info/

I own :

3 R1150-GS (One of them in California) which I consider the best bike BMW has ever built, very good at anything you throw at it.

I also own a R1200-GS, which is also excellent, although it is not as comfortable as the R1150-GS :D

Check http://www.bmwgs.com/forums/forumdisplay.php?s ...

Every time I hear someone asking for comparisons between "any bike" against the R1150-GS, I look forward to see the replies, why?

The GS is a bike built with every aspect of motorcycling in mind.
* Transmission :)
* Paralever/Telelever suspension system :)
* Great ABS brakes :)
* Crossed spoked ...