Steveo I use in both my 89 GSXR oiler & in the 96 GSXR race bikes Castrol active 4T.
I have tried all the latest synthitic's & for our old clunkers it was more trouble that its worth.
I had clutch slip with the FZR1000 on synthetic. Rebuild the clutch & renewed it with 35% stronger springs & it still slipped. Changed to minaral [Active 4T] oil no more slip! Tried it in a couple of my V8 racecars & wasnt happy, so I went to a good quality semi synthetic & they were much happier.
I have just freshened up the 96 engine & after a year of racing it was as good as the day it was rebuilt.
So IMO, for current/new bikes synthetic for sure, but for us good minaral is fine.
Twin electrode plugs 1 heat range colder for the plugs. Get onto Motofix at Tumbi he carrys them in stock.
Just my opinion.
