I've had a lot of NSX experience with dealers and independents in the area.
For some routine tasks - oil changes, brake work, tire replacements - you can take your NSX to any competent independent mechanic. These systems on the NSX are similar to most other cars. Just make sure you point out the three jacking points on each side of the car, and instruct them not to lift the car from anywhere else.
However, for anything other than that, I would NOT take my car to an independent mechanic. There is no independent mechanic in the Chicago area that has a lot of experience working on multiple NSXs all the time, so they aren't familiar with the more complicated procedures, and haven't learned all the "gotchas" and short cuts. They also haven't seen enough cars to be familiar with the common problems.
For NSX work, there is one dealership in the Chicago area that I trust: Muller's Woodfield Acura, in Hoffman Estates. They do far more NSX service work than any other dealership (or independent) in the area. Ted Czarnacki, their top NSX tech, has been working on my NSX since it was new, 17 years ago. He has dealt with many of the most frequent NSX problems on it. When my NSX engine failed (the harmonic balancer pulley came apart and dug into and then through the timing belt cover, causing the timing to jump) and needed replacement, I had it towed to Muller's and Ted did an excellent job on it. He was equally capable of rebuilding as replacing - he's rebuilt NSX engines before - but it turns out that, in this case, replacement was the most cost-effective option.
I also trust Acura of Brookfield, in suburban Milwaukee. John Vasos and his two lead NSX techs, Bill and Steve, do even more NSX service work than Muller's, in fact the most NSX service work of any shop in the entire Midwest. They also have a lot of expertise at racetrack preparation of the NSX. When I need work done that is specific to the racetrack (e.g. replacing my brake cooling ducts), that's the place I go. They also have a lot of expertise in aftermarket modifications; for example, they have installed superchargers on over 40 NSXs. So if I wanted to install forced induction on my NSX, that's the place I would go. They also tend to be somewhat less expensive than Muller's. However, it's a hundred miles each way, and a lot of time in transit, so that's the big downside for Chicago-area owners.
In the Chicago/Milwaukee area, we're fortunate to have two excellent shops with so much NSX experience between them.
I have tried several other shops in the area, without any other strong recommendations. Pauly Acura had two excellent NSX techs, Chuck and Craig, but my understanding is that both have left there, and I am not familiar with the level of expertise of their current techs.