I recently did the PCW clutch kit, w/the extra full friction disc (o.e.m. disc) to replace the 1/2 disc; and the PCW heavier diaphragm spring, and a new engine cover o.e.m. gasket. Installation was a breeze and the PCW diaphragm spring holds better than stock w/o the DD (double-diaphragm spring) increase in pull. Cheaper than the Barnett coil spring conversion, too.
I used to change all my bikes over to Barnett friction discs, 'back in the day,' but got tired of the way the plates stuck together where you would stall-out the bike the first time releasing the clutch after it sat overnight. I dunno if they have solved that, but the Yamaha clutch friction dscs have worked OK for me.
If you buy the exactrep 'peek-aboo' billet side engine covers, then you need some magenta pressuree plate color to justify $600 perspex side covers (ea.!)