TallboyLT is an incredible bike for socal trails and the sierra. At 6'5", you might run an XXL also. That bike remains one of my favorites of all time, great climber, and you can rally rocky chunder like a champ. Might not win a dual slalom, but everythings got a give and take.
Definitely get the burly rimsat your size though, and build your wheels with straight gage spokes. That will be where things get loose.
Good luck
@TracerTong, did you expect that joeg would tell you to get anything other than the TB LTc? The XXL TB LTc is the only non-XC bike in their lineup that properly fits someone who is 6'5" until you get into the V10.