Ive just been in the same boat with it, the way i looked at it was one fault would probably cost you the price of the warranty quite easily.
If your selling soon too, would be a big bonus over the others for sale, as renault doesnt have the best reputation.
Also, my door handle switch packed up just before the warranty ran out, so that was the deciding factor. I havent used it yet, so cant comment how good it is mind you.......