I haven't tried them on a Clio, Woody or someone else is probably a good guide for that.
I had them years back on a heavier MK4 Golf, they were fine and night and day difference... but then we're talking about necessity, trying to make a pig in knickers handle.
The Clio is already a fine handing car, IMO coilovers are a pointless waste and just vanity.
Trackdays are about having fun, no who is fastest, you'd be better served buying a cheaper option if you must have coilovers and spending the rest on tuition. Expensive kit doesn't make you faster, it just increases the speed at which you have accidents.