How many different type of Ohlins out there for Evo? Any negative feedback?

 

Ohlins are solid, only complaints are big $$,

Works sells a nice range pre set-up from 2k-10k$

Muellerized, RRE

Vishnu... Many others

 

Any difference between the 3 tuners RRE, Vishnu, and Works?

 

yep. All three tune their shocks differently (valving, spring rates, etc.) to suit your driving style.
I personally like the attention to detail that John Mueller (RRE/ Muellerized...) puts into his setups but I've also heard good things about the Vishnu setup and WORKS has just recently become an Ohlins certified repair/rebuild dealer (of the three I think their the only one).
Pete at WORKS and John at Roadrace are both great guys and won't steer you wrong. Good luck...