Few years back, just around the time I bought my 2000 NB, there was a story in Road&Track or Car&Driver (can't remember which) where they lined up a bunch of sports cars and a couple of pro drivers on a road race course and did a stopwatch comparo. Idea was to figure out which car was the fastest, mixing classes and types of automobiles. Among the contenders were Miata (of course), Corvette, M3, 911, Elise, S2000, 360 Modena, Viper, etc. Maybe there were 10 cars? The Elise was supposed to be the "ringer" but it didn't come out on top. Idea was to allow all of the drivers drive all of the cars, average their track times and pick the winner. So it wasn't a raw-numbers thing as far as lateral grip or slalom time, but had to do with how easy the car is to drive.
Anyway, Miata finished near the top but not absolutely on top, but did amazingly well considering it had 1/4 the power and 1/8 the pricetag of some of the cars in the lineup.
Some of the comments about the Miata from the drivers showed the real point. They said while the Miata had lower limits for absolute cornering than, say, a Viper, they said it was possible to drive the Miata beyond the cornering limits... drifting every corner, walking it around corners, etc. But that going over the limit in a Viper was such a disaster that you had to drive under the limits all the time. So the measured limits did not correlate to the performance. Even with a major horsepower and numbers handicap, Miata performed in the top of the pack because it could be driven faster around the track, regardless of the limits.
So the ability to drive over the limit, recover, control the car when it's in a slide, predict the behavior of the car, stability of the car over the limits, etc., all affects how the car "handles" and also how fast you can drive it.
For example, I had a VW Jetta GLI 16V with full-blown race suspension (and street tires) that drove on the street like a go-cart. It was crisp, nimble, lightweight, would corner VERY fast, had insanely high cornering limits, etc. Really, below the limit, in an entirely different league from a Miata. But woe to you if you imbalanced the car in a corner. Lift the throttle just a LITTLE BIT inside a corner and you were going to very rapidly swap ends. Brake hard on the way into a corner was a sure fire way into a spin. You had to throttle through corners and know exactly how and when to brake, steer, etc. It took a much higher amount of skill, and more margin, to drive the car. After the rod bearing went out on that car, I bought my 2000 PEP Miata and even with the factory 14" wheels/tires it would go through any corner faster than my racer-boy 16V. The reason is because I could drift controllably around a corner in the Miata, feel it slowly coming around and bring it in, brake inside a corner, hey, the car's forgiving. Under the limit, yeah the 16V felt a lot more like a go-cart. However, in the end, I guarantee my bone-stock Miata is a faster car in the hands of most drivers. Someone specializing in driving front-drive VW's with enormous amount of roll stiffness in the rear could probably make the 16V go faster, but that would take really special skill. Miatas are fun and fast every day, for any driver.
This is the same thing that made Datsun 240Z's such popular and fun cars for most people, even though there were certainly faster and more powerful cars out there, the Z cars dominated on the race track. Balance, poise, ease of recovery, and predictability are all very important in a sports car. In fact, I'd say these factors are what separate a "true" sports car from a car that's just a sporty-styled "fast" car.