Pretty sure it was more than 1kg per corner but can't remember now, did it years ago. The 19" Pretoria with tyre was close to the same weight as a 18" Pro Race 1.2 wheel with a tyre.
As for the rep's seeming stronger, VAG will spent all sorts on testing components and that the cheaper option won't used for good reason. As for reports of damage, there are loads more original Pretoria's on the road than copies, which would account for more being damaged, and from the folk i have seen report damage, most of the time due to crap road surfaces or people running them underinflated.
I've read all sorts from those who will try to justify spending less on something that looks similar. In my many years of messing with cars, i have yet to come across a rep that was in fact stronger than an original wheel, and in this case, even if it was (not sure how that would be possible based on the composition of the material used), it definitely isn't lighter (which makes a notable difference to performance and handling etc).
Do a google on it - the same things pop up time and again about replica wheels..
Disadvantages of Replica Wheels
Often use lower quality material prone to cracking
May not meet safety regulations
Can be much heavier than OEM wheels
Can reduce value of the car compared with OEM
May require adapters or spigot rings to fit properly
People (correctly) have an issue with the horrendous cost of a genuine Pretoria wheel from VW and it is known that you can get a set of copies for the price of one new genuine wheel from VW. Personally I'd sooner spend money on a properly designed aftermarket wheel that is decent in its own right than something that looks similar to an OEM item, but isn't the OEM item.
I have a set of black genuine 19" Pretoria's in the garage - they are very very pretty