FINE! happy now?
If you hopped in the car and drove it with the bigger wheels on it, you probably wouldn't know the difference, especially since you don't have a reference point. If you want to see if you can tell the difference between them, drive with the bigger ones on then swap to the stockers. I am willing to bet you will feel it. Wheels tend to come down to personal preference but most folks with Miata go with 15" as the best overall size.
And I can't figure it out, where is NL?