I’ve run 36s on two Fives, my previous (an 09) and my current MY2010 one, in both cases Float Rs.
On the first one and set to 160mm out of the box they were fine on lift-assisted stuff but the bike felt sluggish and, like Mildred says, lost its zip. Solution? I chopped the travel down to 140mm with a spacer from Mojo (a quid or something) and best of both worlds – burlier front end and extra stiffness but geometry back to where it should be. Felt like a different bike.
I’ve got my current ones set to 150mm and that feels fine too so seems a fair compromise but I’ve got the 20mm spacer too should I want a more trail-friendly set up or the option of removing it totally for 160mm of goodness for the Alps.
If you ride hard I think 36s are a good choice and certainly bulk the bike up a bit.