I was given a s/h pair in reasonable nick and they were OK, rolled and gripped well. No downside (price I guess) How much of a benefit over any other decent tyre at a similar price point is a moot point. You need to have aero front wheel etc. and be quick to realise much advantage I reckon. But reasonable idea, just unsure of the real-world benefit for regular mortals on the usual crappy roads we have.