There's a post elsewhere warning of T66s being "lethal" in the wet. Well, I rode all last night and this morning in torrential rain, very nervously after taking heed of the tale of four bikers hitting the deck in the wet all shod with T66s. After a while I started riding faster and faster, seeking out overbanding and white lines, trying to get the back end to go all "scurrelly" (the established GS term now for rear tyre skittishness in wet conditions) and just couldn't get the things to shift an inch. Had a hoot riding faster than I normally would in such conditions.
Conclusion:
There are two types of rain - (1) "slippery" rain and (2) "sticky" rain. The last 24 hours has obviously seen a lot of sticky rain.
Seriously, Metzeler Tourances or Enduro 4s are more confidence inspiring in the wet, but T66s are good tyres for the GS (crap on a Varadero though).
Simon E.