I'm an aggressive B rider. I weigh 140 lbs. The 5w oil works great and is all I use in all my forks.
Know that just because something says it's 5wt, or any weight, doesn't mean that's the actual weight. To truly know you need to find out what the spec of the viscosity at 40c is for proper comparison. The oil I run is 26.1 @ 40c.