Only intentionally...very straightforward...starts winding up faster after the first couple of turns and takes a little longer after recovery inputs to exit the spin. I wouldn't attempt them solo unless you're comfortable with spins.
 
We did 6 turns each direction back in the early '90s. It gets your attention to say the least. Took 1-1.5 full turns to recover.
Rotates very fast after the first 1.5.
After the first attempt, Van turned spin testing of the -6 over to Bob Herendeen.

I believe that Van now recommends no more than 1.5 turns.
 
I haven?t spun mine extensively, but I have found that spins in my RV-6 (O-320, wood prop, sits pretty far aft in the CG envelope) have been predictable. However, as Mel indicates they change in character after 1.5 - 2.0 turns. For a 1 to 1.5 turn spin the airplane recovers very promptly as soon as you remove the pro-spin control inputs. Beyond that it takes more time, but recovers well with the recommended control inputs. I?ve not spun mine more than three turns. That occured as I was working towards a 2.5 turn spin, and it did not recover until about three. Six must get pretty sporty?

YMMV

Doug