As stated, they are quicker than a '99 -'05 Miata, the later ones had a limited slip. They are better built than the Miata in my opinion, and nicer inside, as well as having MUCH better seats. And I have a '99 Miata so I'm not really biased toward the MR2 Spider.
They aren't the best looking car out there, but if you like them, that's not really an issue. Otherwise, the motor is for sure in the right place, driving the correct set of wheels!