I don't have experience with a S2000, but I just took delivery of my new Spyder on Saturday after 16 years and 236k miles in my Pontiac Solstice. The cabin is very similar. The gearbox is amazingly similar in position and throw. Going to take a little time to develop the muscle memory to make the shifting smooth in the Spyder. The ride in the Spyder is great, not too harsh (IMO) if that's what you're worried about. The suspension does a good job of dampening the minor bumps in the road. You won't be bouncing all over the place as if the car has no suspension. That was one of my concerns. I'm finding it quite comfortable as a daily driver. Granted, that's from someone who has spent the last 16 years and 236k miles in a Solstice that has no suspension left and prior to that 12 years and 215k miles in a Jeep Wrangler. My butt is desensitized to bumps in the road. As for noise levels - they don't bother me. It's a convertible, you already know you are not going to have a whisper-quiet cabin. There is a constant whine (poor choice of adjective, sorry) of the engine, mostly coming from inside the cabin, but you should be used to that if you're a long-time convertible driver. I'm still in the break-in period so I don't know how loud it will be above 4k rpm, but I don't anticipate doing extended highway driving above 4k rpm so that's not going to be an issue.
If you haven't locked your spec yet and you have any concern over choice of radio, I'll just say I am very happy with the Bose system. I've heard others rave about the Burmester system and say it's definitely worth it, but my joe-average ears are quite content with the Bose. I'd love to hear how good the Burmester is, but I still don't think I'd be willing to pay the extra $ for it in a Spyder. In a luxury sedan, maybe, but not in a loud Spyder. But, if you're blessed enough to not have to worry about the extra $$$, go ahead and order the best of everything.