I agree that the 288 front brakes with ATE callipers were border line inadequate in my 2000 VW Passat 4Motion but it weighed a lot more than the current Polo 6C, and probably very "wooden" in feeling, but on my wife's Aug 2015 Polo they seem good, also I'd agree about no initial bite, that is where the brakes in my 2011 S4 give a lot more confidence, although as you might expect lots of B8 S4 owners go for at least S5 brakes.
Edit:- probably what I meant to say was, if that
Ibiza only 90PS or 110PS and very light, there might not be much to gain in uprating the front brakes, look good though and limit the minimum size of wheels that can be fitted which might mean less suitable winter tyres is the owner ever needs to use them.