Before that I was using aftermarket 15s which come with the car.
Those were quite very heavy, up to 10kg each one, while the sport wheels only weight 5,9kg each. I noticed a HUGE difference, both on acceleration and handling.
First picture, taken during a trackday in Brands Hatch i was running OEM springs with Koni Yellow Shocks, so it gives something like a 1cm drop.
Second picture, with my current setup, Mk2 AGX Schocks with matching Flyin Miata springs & mk2 top hats, I've measured i have 12.75" ride height on the front and 13.25" on the rear (measured from the center of the wheel to the fender lip).