While Redline MTL is an excellent product, it's not what is specified for our K1200's.
MTL is class GL-4, which has friction-modifiers for syncro-mesh transmissions and is 75/80wht.
BMW specifies class GL-5, which has no friction-modifiers, and 90wht. gear oil.
People on this site use a lot of different gear oils and weights. I use Mobil 1 75W/90 only in the trans. and rear drive.
I'm sure there will be many different opinions and replies to your post.
'04 K1200RS Capri Blue(totaled)
2008 Triumph Sprint ST