I think that when it comes down to it, the driver will make the biggest difference. A competent driver in either car will always make the best use of each car's characteristics
I had a 172 Cup before I upgraded to a 225 Cup and based on my experiences on both, the Megane is quicker although it doesn't feel it. The Meggy gets to the speed with less effort and in more comfort whilst the 172 was always a bit noisy.
As for handling, I'd still take the Meggy, it feels more planted in the corners and it gives you the confidence to put it in to a corner, knowing that you'll come out the other side. The Clio was always a bit skittish, especially where the road was poor.
The only criticism that I have with the Meggy is the lack of feedback you sometimes get with the steering, it is minor though and once used to the car, you'll adapt quite easily.