Originally Posted by GSMarc
I tried the bike today in the showroom (just sit on).
It was told that the new R1200GS was thinner than the previous GS.
Do you confirm my feeling that it's still larger (between the legs) than our HP2s
I cannot confirm (as I don't own HP2 but I've been on it in the past), but I think that you are correct. The difference is the seat. Your HP2 (MM) has a thin "enduro" seat.
That said there is an enduro seat for new GS too (that is indeed thinner than the standard), but don't know how it relates to your seat.