I'm pretty sure a Miltek, Piper, or PipeWerx decat aint much more than that. I'd personally pay a little extra for a known and proven brand. Unless anyone can post up who has one and comment.
 
i cant seem to find any known brand ones though :S they seem to do them for the cupra r but when it comes to the leon cupra its all sports cat :S
 
blueflame and piper do one for about £200 and after the carry on ive had with exhausts id pay extra to get a decent one you got some come back with if owt goes wrong
 
I had one on my Mk1 Cupra and it was fine. I had troub;le mating it to my Milltek rear system but I suppos eit depends on what you have.

I would say they are fine, after all there isn't much to a decat anyway!! You may need to buy and weld on a coupler but that's about it and may not be necessary