In case it is any help - the super softs have lasted pretty well for a whole year's sprinting - that includes Llandow and Pembrey - possibly the most severe tests. Doubt they will last another year though! Not sure how much of an advantage they were and it felt that they were probably going off on the second lap at Llandow - but by then you are pushing much harder.
having said that, for the same price, and assuming they were available , I would go for them again. You never know, they may justy give you an edge 😬
Mike