Do not use the pure one filters. Even purolator recommends against using them for motorcycle applications. if the MFG says don't do it, then I'm not going to take the chance.
I used to use the purolator filters as they could be had on Amazon for like $4 each. now they are up to $8 or so. Still cheaper than the $14 I remember paying at the stealership for an OEM one. I am going to start using Amsoil 10-40 and filter in the RC. Filter and a gallon of oil will run about $50.
For my CBR, i used to use Repsol, then switched to the full synthetic 5w-40 Rotella T-6. I noticed 3mpg improvement, a smoother running bike, and better shifting. at half the cost of the Repsol, it was a no brainer to keep using the stuff. I'd use it in the RC too, but the 5 weight has me a bit worried with the piston size and heat that the engine generates. if I knew I'd have nothing to worry about, I'd use it as it is half the cost of pretty much anything else out there.