I went through a whole range of springs, oils and settings with my RS front end - spent a small fortune on it and had the forks apart more times than I care to remember. The best set up for me is standard springs and 5w belray oil. There are 3 small piston rings on each the dampers, these should be regarded as service items, I missed them initially and just could not get the front end to work properly.
Motobins do a full service kit for the front end with everything you need. The Aeroshell 4 oil caused me lots of problems, personally I'll never go near the stuff again but I'm sure lots of people get on well with it.