From my experience the original set up was a little agricultural and traditional in feel, if you like to drive slow in fast out on good tarmac it's fine, also the rear would sag with two up and loaded with luggage on a weekend trip. The SSL set up feels very different with near neutral handling in the bends on dry roads and does not sag when fully loaded, the ride quality is also superior as the jolts over poor surfaces are smoothed out.
I have my shocks on mid setting and have not felt the need to adjust them.
I fitted mine in around 5 hours just taking my time and had no problems.