I had the works suspension put in a few weeks ago. My old suspension was the early SS (not the SS+, and before MINI softened the suspensions across the range). The works suspension does make the car make more noise going over bumps, but the ride doesn't feel much harsher. I guess since there's more noise, there is less compliance in the suspension. But, it's not horribly harsh.
On good pavement / highways, the ride with the works suspension is more comfortable than on close to worn out (77,000 miles) stock suspension parts.