I recently joined the 17" club and I'm here to stay.
After coming from 19s the car feels 100% better to drive with more sidewall and half the weight per rim.
I'm currently on 235/40/17 because they were on the wheels when I bought them, but I will be going to 235/45/17, which will be even better still.
It's pretty much ride, handling, performance, tyre price vs looks and I'm now slightly less shallow

They don't actually look that bad aside from the fact they are 7.5 +50, so I have a bit of the old sunken look, but if I was ever to make these track wheels and get some wider 17s for street I would be happy with the look.
Plus 17s are more sleeper.