I weigh about 62kg's and ride the 6" wheels mostly on pathways and road.
I went from the standard Black 90a to the Performance Yellow 92a bushings as I understand that these use a different formula and are supposed to feel softer, but wow...they have a very different feel! Not bad, just different. Despite being a higher durometer, they feel much softer than the originals.
I'm going to give these a few more rides to see how I feel, but there's a high likelihood that I'll be ordering a set of Light Blue 95a's.