Had a 1991 NSX for 7 years prior to the owning and F355 Berlinetta for the last 2 years. I have not had many issues with either car, the maintenance is more expensive on the Ferrari, the engine out major service is only required every 5 years, not every 3. I drive my cars hard (both visited the track more than once), not used for cruising or putting them in front of restaurants and both proved to be reliable.
The Ferrari is considerably more fun for me to drive, but if you asked was it worth the difference in price and maintenance, I would be hard pressed to give you an answer. Issues with F355 are as follows: headers will go bad for all years, valve guides have gone bad on all years (including some 1999s), cats will go bad and interiors will get sticky. Good news is some of these fixes are not only permanent, but provide upgraded performance. I went with Tubi header, hyper flow cats and Tubi muffler, valve guides had been replaced on my car. Much debate on what is the best year, 1995 is OBD1, and has 5 hp more, some bugs worked out on later years. Key to owning the Ferrari is having a great independent mechanic close by, the dealerships are not that great, at least out here in the Rocky Mountain region, but we have one of the best independents in the country. Cost of service as well as quality of service is superior with independents such as Scuderia Rampante, Brian Crall and Eugenios. As mentioned previously it is difficult to beat the engine note in an F355, but it sounds better from the outside than the inside, opposite of the NSX which sounded great from the inside). Inusrance is not bad on the Ferrari about $1,000 per year, similar to what my NSX ran
The NSX was a great car and I truly enjoyed it, it handled great, was super reliable and was rare. The only issues I had were that the engine note did not stir me enough (made the mistake of putting a B&B exhaust on and it only made it boomy) and it could have used a bit more power (I live at 7,300 feet high, so the altitude robs both of these cars of considerable power). Exterior fit and finish were superior to the Ferrari, interior materials we inferior as it relates to quality (tough to beat the Connelly leather in a Ferrari) but much more durable and far less maintenance than the Ferrari.
Neither of these cars are much fun for me to take out and leave anywhere, I was always paranoid someone was going to mess with either of them, I truly enjoy taking my wife's S2000 out, we can enjoy dinner out and not worry about the car.
The only way to really determine which is for you is to:
1) Drive them both and determine which one really makes you smile
2) Determine which one your budget or tolerance for expenses is on an ongoing basis, if a big bill hitting you unexpected will do to you financially and emotionally.
I can say that while I do miss the NSX and loved having it, I will probably never let go of the F355.
