I never said that the NB is anywhere near as stiff as the NC. What I did say was that additional bracing would likely make the NB stiffer than a stock NC. No, I cant prove that, and neither can you prove your side of the story, so let's just leave it at that.
I have experience with the cars to back up my claim. Yes, it's not as good as numbers, but it's better than nothing. What direct experience do you have?
I believe the original issue at hand was NA vs NB.
The original issue at hand was "Is the MX-5 a girly car." We've gone well past that.
The weight difference is what, 20lbs maybe? That's negligible. Additional chassis bracing that made a soft car more rigid - a bit more important, no?
The weight difference NA to NB is closer to 100-200 pounds, for similar trim levels. Early NAs were around 2200 pounds, later NAs around 2300. NBs are around 2400, with the Mazdaspeed being in the 2500 range. This varies from car to car based on options and, by now, differences in how the cars have aged. But it's a lot more than 20 lbs. The
listed curb weights on Wikipedia are either a bit optimistic or not US-market, but even there, a 250 pound difference is shown between the NA and NB.
The one and only thing that you've mentioned where the NA has an advantage over the NB is weight (see above - its hardly a difference). The NB is stiff more powerful, stiffer, I believe has bigger brakes, etc. The "oh well I can mod the NA and make it stiffer than the NB" argument is like saying that a GC Impreza is better than a new STI because you can swap an STI engine/drivetrain into the GC. Mods are a whole new ballgame. Stock-for-stock, new STI is better than old NA Impreza, and NB Miata is better than NA Miata.
You continue to use hyperbole. Try making your claims without the hyperbole and see how they stand up. There were a lot of little changes between the cars throughout the years, so pointing to exactly what makes which one better is a bit difficult, without picking a specific one. But one difference is the NAs pre-1996 are not OBDII, which helps with passing emissions testing in many areas, helps with tuning options, and in general gives the owner a wider array of toys they can play with. The 1.6L engines in the early NAs are a bit more freely revving than the 1.8Ls (yes, in the later NAs as well as NBs), which helps with that difficult to define "fun" factor. The lightest OEM wheels for a Miata were found on the NA. And NA/NB Miatas are specially sensitive to wheel/tire weight.
Research, reading facts and figures, you know, the usual lot... rather than just what I thought when I drove both. Oh, and maybe its just me, but I think that if a car is better than another in virtually all areas except that its 20lbs heavier, its the better car.
Hrm, research. Yup, I've done that, too. I've done a lot of that. I've also driven quite an array of Miatas. However, I'm not sure I trust your research, since you were off by, oh, around an order of magnitude on the weight difference.