It depends on a lot of things. Are you referring to the car in it's 1991 specs with 205/225 wheels and tires? Are you referring to what you can fit under the stock fenders (235/275)? Are you referring to what you can fit under a widebody?
The performance of hte 205/225 equipped cars is not up to par by todays standards. Throwing a 215-235 front and 265-275 rear tires makes the NSX 'current' from a tire width relative to body weight standpoint.
As far as weight goes. I removed the spare tire, added a STMPO aluminum rear bumper, Downforce carbon side vents (actually a big weight reduction) and the Downforce NSX-R wing (another big weight reduction) and my car weighs 2,820lbs with a touch-screen navigation, subwoofer, amp, stock seats, a/c, and full interior. This is a good 2-300lbs lighter than a F430 Scuderia (with no radio), GT3, and many other modern cars.
The N/A power is not comparable to a GT3, F430, Z06, and a S2000 is comparable if not quicker with similarly light modifications on track. But this can be fixed with forced induction -superchargers or turbos.
BUT, the chassis is marvelous. I'm not a big fan of power-steering equipped cars since I havn't tracked any well-sorted cars, most of them have been stock. Also for track use, the coupes have much greater chassis stiffness. The unsprung weight, handling characteristics, and suspension dynamics of the NSX is extremely impressive to be this good 15 years later. With a competitive tire size (235/275) the NSX's chassis can perform extremely well.
The chassis is also takes additional power VERY well. How good is the chassis? If you think about it, our FX750 NSX had STOCK suspension geometry, control arms, pickup points, and shock mounting points. Realistically it was a well sorted stock chassis (obviously gutted) with racing slicks, a good set of coilovers, and was turning times as fast as a Daytona Prototype or ALMS GT2 cars -which are all heavily modified tube-frame cars, or at least have different subframes and pickup points from stock. IMO this speaks worlds of the stock car's suspension geometry and chassis to be able to handle 800hp, racing slicks, and be able to handle and turn times as fast as $300-750K racecars.
Having driven GT3s (still one of my favorite track cars), 911 Turbos, F430s (also fantastic on track), every year GTR from R32-35, M3's, you name it, I still think the NSX's chassis is marvelous. Sure it dosn't have power steering, but if anything I would call that being 'more manly' and 'pure' in terms of driving experience. Sure GT3s and said cars have power steering and are physically easier to drive, but the NSX's chassis is a great platform and I might argue, is as good as most of said 'current' cars. After driving all of these cars, I still really enjoy driving the NSX.
I am also far from a fan-boi. I love the NSX, but its not the greatest car ever built. Sure its good and you can call it great, sure I really like mine, but it's just another car. Its quite a good car but it's not my entire life, its not the only good car out there because there are thousands of awesome cars that are fantastic to drive on the track. But I don't think its fair to say it's obsolete or out-dated, and I think that speaks wonders at how good it is by modern standards for being so old.
I've tracked every GTR out there, 360s, F430s, GT3s, 911 Turbos, M3's, EVOs, STIs, S2000s, Corvettes, Mustangs, and many more on a regular basis. After driving all of that, one of my favorite cars that always stuck out in my mind was the first FX500 - 500whp turbo NSX which will wipe the floor with F430s, Gallardos, GT3s, etc... Sure the power isn't fair, but for relatively little money, the NSXs chassis with that much power is a dream to drive and more than capable. Since then i've always wanted one and was lucky to become an NSX owner 2 years later.
The NSX also has many advantages aerodynamically and from a layout standpoint. It has been a great platform with such high capabilities that FXMD was able to constantly build off of to have one of the fastest Time Attack cars in the country/world. Wait until you see the re-birth of the FX750 to see what I mean.
At the end of the day, I don't think it's fair to criticize the NSX's chassis and say its out of date. Sure its limiting factor is how big of a front tire you can fit, but with a liveable 235/275 tire package and a supercharger or turbo, I would say its more than relevant to anything on the road today.
I honestly don't care to argue this point or to try to convince others of this. Take my comments with a grain of salt and do what you want to do and what suits your needs or happyness. No 1 answer is right for anyone. Take my thoughts for what they are worth, and that there are TONS of great cars out there. But a 500whp Turbo NSX is near the top of my list along with a GT3, F430, 993 Turbo (and Ruf CTR2 that I drove), and many more.
The NSX isn't the greatest car since sliced bread, but it is a great car that can with some modifications, hang with anything out there.
Billy
Edit: Quick and somewhat scrambled together info:
Engine:
-Not too much you can do NA to be competitive with modern supercars
-No torque NA, but rev-happy with modern by today's standard's high 8,000rpm rev limit.
-Needs a Turbo or Supercharger -and with that, is able to be 'current'
-Stock oiling system (the oil pan) is a terrible design and NEEDs a baffle for heavy track use.
Transmission:
-6-speed not as robust as the 5-speed for high HP applications.
-5-speed's US gear ratio is imbalanced with an overly long 2nd, and short 3-4 and 4-5 gear changes. The Japanese gear ratio set is much better.
-Japanese 5-speed's gear ratio's 3rd gear is known to be weak at high power outputs.
-Stock LSD dosn't work too well and should be replaced with a clutch-type unit like OS Giken -which will increase stability of the car and make it easier to drive.
-Shifter's "bolt-action" is world-class and was the benchmark for the Ford GT's shifter feel.
Tire size:
-Definately a weak point with 235/295 being the widest sizes fit under stock fenders. Going any wider, the tire rubs well before full lock which makes the car less practical for a street car.
Brakes:
-I really don't think they are as terrible as everyone says when using aggressive track pads. Either way this is easily solved with a bigger calipers and rotors.
-An ALMS/Prototype quality brake system (Performance Friction) is available for the car which makes the NSX more than capable for absolutely anything.
Chassis/Suspension:
-Strong point (coupe), able to handle TONS of power without ripping the subframe out from under the car, or any other limitations.
-Bumpsteer isn't terrible in the car, suspension geometry and aluminum design is superb.
-Non power steering cars have great feel and is very 'pure' driving experience, very communicative. But a nice power steering system makes cars easier to drive in the modern world. So non power steering can be viewed as a weak point. I'm currently not a fan of PS equipped NSXs.
-Great suspensions available for the car and the NSX's suspension layout, design, feel is current by modern standards IMO.
Ergonomics:
-Not enough head room for tall people.
-Trunk becomes a cooking oven (great for pizza delivery)
-Trunk isn't that big
-Forward view out of the car is superb
-Seating position is awesome
-Pedals are very good for a Japanese car