A way to look at what Psycho is saying, anytime you can reduce the sidewall you will improve your handling by improving the response. The trade off is that you don’t have as much tire to cushion the bumps. In my opinion the 15 is the way to go if you are wanting to keep the car more like an original. (Plus, I like the look of the 15 over the 14
) You aren’t going to loose that much comfort as you would going to a 17 or larger wheel. Plus, as Psycho also pointed out, there are a lot of options for tires to fit a 15inch wheel.