If all you want to do is turn, its an incredible car. Out of the box, despite what people say, its total bullcrap. The factory 75 sidewalls are so limiting that I could probably outhandle it in a stock random solid rear axle american car. They are ridiculously annoying.

Once you get some wide tires without sidewalls, you can go crazy at autox. Stiffer suspension, chassis bracing (convertibles blow so much), strut tower bars, anti-sway, etc. will all help further.

Straight line is dumb as rocks with the 1.6. I made the mistake of accidentally getting a 1.6, which is inferior to the 1.8 in all sorts of ways. The engine can handle plenty of power (already being built for forced induction; see 323 GTX) but the differentials are "cute" at best (S2000s and 1.8s share the same innards) and the transmission cant handle stupid amounts of power forever, but its great otherwise. You dont really want stupid power in one of those anyways.

IMO its perfect for a drivetrain swap of your choice. Even if you stay 1.6/1.8, I suggest a better diff (at least the 1.8 diff) and then you're good to go for years to come.