I haven't even had mine for 2 years yet. The Mk6 isn't worth it as it doesn't really bring much new to the table. Don't get me wrong, the Mk6 GTI is a cracking car, but it's not worth breaking the bank for when I already have a great car.
Perhaps in 2/3 years time I'll look to change and the Mk6 may be an option. Although I'll probably wait it out for the Mk7 whenever that will be.