After owning two NA Miatas (and a stint on staff at the short-lived "Forever MX-5" magazine), a good friend offered me a killer deal on his 2006 NC. My only experience with the model was a short drive in my friend and former editor Jeff Zurschmeide's Club Edition, which was the Mazda press car; he bought it from Mazda when its duties were done.
My immediate thought on pointing the Club edition PRHT into the first freeway on-ramp: "Well, they didn't **** it up." It felt bigger, slightly heavier, and seemed to slot midway between my first NA, a '96 which I'd set up for track days and autocross, and my second, a '96 M which had stock springs and bars and KYB Gas-A-Just shocks courtesy the previous owner.
The seller of what is now my '06 NC had previously installed the Flyin' Miata II suspension kit with adjustable Konis; he went with the Racing Beat bars (hollow in front), and it was his autocross toy for a couple of years.
I'd add one item to Keith Tanner's excellent list of advice: Spend $150 or so on the Moss Miata fited luggage kit, at least if you enjoy road trips with a sympathetic partner. We took the NC to Monterey for Car Week, first in 2021 with a mixed set of luggage, then in 2022 with the bespoke set.
The lovely-and-talented was able to get a week's worth of outfits in 2022, and most importantly, "enough" shoes. Considering we spent our days at Laguna Seca and Pebble Beach and our nights at The Sardine Factory and other MOnterey night spots, this is mission-critical work here.
I miss some of the feel of my NAs, which always felt like the best MGBs ever made: light, tossable, and almost prescient in their response to corner entry and exit: the apotheosis of "jinba ittai," "horse and rider are one."
The NC... well, for the 2021 Car Week, I had an assignment to drive five classic Mercedes SLs brought to Pebble by the Mercedes Classic Group. (STILL the best day I've ever had at work.) The star, pun very much intended, of that was their 1957 300SL roadster, which still felt as if it had been hewn from a solid block of unobtainium. I couldn't help but think of the old saying about Michelangelo carving a block of marble and removing everything that wasn't David.
The NC, compared to my NAs, felt very much like a step or three in that direction: not quite as solid or of-a-piece as the SLs, but with more chassis rigidity than the earlier cars, as well as more room in the interior and the trunk.
We put nearly 3000 miles on the NC each year, driving down from home on the northern Oregon Coast and back. The Oregon Coast is either a wonderful or a terrible place to have a convertible: terrible because it rains for months on end, but wonderful because when the rains finally stop, the views (and some of the roads) are simply incredible. As I learned with the two cars in my profile pic, you just have to learn to say, "Well, it's not raining NOW..."