Welcome to the new and improved Proflex / K2 Tech Forum!
I didn't want to change ANYTHING when I upgraded my rear shock in my disco monkey, so I went for the vanilla R, I love it and is a great balance for the psylo, (6" rear-5"front) and since I didn't filed it, change wheel size, or streched the frame (I machined to a perfect fit) the frame is still 'new' so whenever I feel ready to it I'll go for a shiver SC + vanillaRC