I have little doubt that the Honda S2000 is a great car but don't forget this is an older car namely at least twelve years old. The Miata can also be had from close to 30 years old to brand new. Parts are readily available for the Miata and can be readily modded.
Having owned my 2013 NC for three years I am happy with it but I can understand why owners mod it for more power. However once started it is a slippery slope as thousands can be sunk into the car and when time to sell the subsequent buyer will not appreciate the $$ sunk into it. The engine will be more stressed but the engine of the Miata is very solid.
Having said that I agree with one whipped puppy that the Boxster is a great car and is a bundle of fun right out of the box. It does not need to be modded(90 mph in third gear).
The Boxster S is even more fun. But with any Porsche you need deep pockets if something goes wrong particularly if you do not wrench yourself.
I still look at ads for Porsche cars. The new Boxster and Cayman are outstanding cars. The new Miata ND or ND/RF are also outstanding with an additional ten more hp in 2019. 0 to 60 mph in an ND Miata is great at less than six seconds.
In my mind the roadster competition is great nowadays. Enjoy your search.
