I love my dad's S2000. Hondas are the most reliable cars on the road IMO, so take that into account. My mom bought a new Honda CRV in '07 and just this past month she went over 100,000 miles on it. Literally not a single problem, only the normal service (brakes, shocks, ect.) My dad bought his yellow S2000 salvaged, and it still has had no problems in the 7+ years he's had it. It's not his DD though, but he's put around 40k on it and it is perfect.
I just don't like how prominent mustangs are on the road. I see one on almost every street. And they're not that good looking as you said.
I'd go with the S2000 for sure.