235/40/19 is about 5% bigger in circumference than 225/40/18, even 235/35/19 is still 1.5% bigger than 225/40/18. Do the 235/40/19's not scrub the wheel arch liners at all?
You may have misread
. The reference to 235/40R19 is to the 159Ti, and was in response to Alexandrus's comment.
I have not/would not use that tyre on a GT. I currently have 225/35R19 on my GT, and plan to go to 235/35R19 for reasons of load index. No scrub at all currently.
19" is definitely a bit bling. However, I can tell you that the performance of the car has not been compromised to the point that I would have it any other way (it's in fact enhanced from standard). Very happy with the state of my car, which is probably more modified than most of the GTs on this forum, but not the most extreme by any stretch.
It is a generalisation to suggest that 19s = too heavy, bad ride comfort. Of course, some 19s will be heavier, and some tyres will ride poorly and tramline. But there's plenty of heavy 16" and 17" wheels too, and poor tyres. Choose carefully, and expect to spend good money, and you'll buy quality products.
18s are a very good compromise IMO, in terms of cost (both wheels and tyres), weight, ride comfort, etc. Very fair choice for most people.