Terrible compared to whatever they are driving.
People don't understand tires. Manufacturers have to walk a fine line between comfort, gas mileage, handling and longer life.
For 99% of drivers out there, the Hankooks are perfectly fine. You can "adjust" the different variables by playing with the air pressures.
On other car forums, the Hankooks are considered a step up from whatever comes standard on those cars.
That said, this wouldn't be a car forum if the lemming mentality isn't that everything the car manufacturer does is bad - the tires are bad, the brakes are bad, not enough power, intakes are bad, lights are bad etc.
The GTI, including the Hankooks, is a great overall package. If somebody says "I'm driving to the limit, I need stickier tires" then they should get summers.
However, I take exception with your position on winter tires. For ease of calculation, let's assume that you are driving 2k miles a month (so 24k a year).
You should switch to winters when the temps fall under 50 degrees or so (so where you are from late August to early June
). Accordingly, you're looking at running winters from November until May or about 6 months.
That means that you are putting about 12k miles on your winters and 12k on your "summer" tires, so if you are running high performance summers, then you'll get 2 years of life from them and probably 3 years on the winters.
I put "summers" in quotes because the type of tire you run in the summer depends on your needs. You could keep your Hankooks, run a better all season like the Contis or dedicated summers. The important thing is to understand that you really should be running winters in the winter because all weather tires really aren't - they are 3 season tires.