My clutch lasted 160K miles, it was very heavy and would judder in traffic on a hot day so I knew it was worn. The new clutch is amazing. Really light and positive feeling. One can just push it up and down without thinking much about the bite point and get totally smooth fast changes. In fact it reminds me somewhat of the clutch in a mk5 golf, another car where the engineers have perfectly matched the characteristics to the car.
Same goes for gear linkages. An S2 and I imagine the 951 as well are an absolute joy to drive when a fresh set of gearbox linkages and clutch is fitted, only modern car I have driven with a nicer shift and clutch combo is the mx5, but the mx5 is more difficult to drive really smoothly.
As for running costs, well looking back over the past few years I reckon my S2 on a per mile basis cost about the same to run as my daily driver swedish dog. If I didn't need a car with 4 proper seats I wouldn't hesitate for a second to go back to driving the S2 as my daily driver, and only car. You don't need another car (well a 3.2 951 but thats a different beast altogether)