If we were that bothered about build quality, we would'nt buy a Renault would we?
I've bought a set for my 172 cup, it's used several times a year for track days so i thought i'd give them a go, nowt to lose. I'm sure when they are set up right they'll be fine, probally not worth corner weighting it with these though. If I like the coilover experience I may get some more of a "better" brand, if I dont i'll go back to the original shocks and sportlines.
We all trust standard renault shockers and they cost a couple of quid trade each, and you would'nt worry about them falling apart would you?