I like the 124 Spyder a lot. I think the lines are better than the Miata, but that is just my personal opinion. In my case the nearest Fiat dealership is an hour's drive from home and the nearest Miata dealership is 30 minutes away. That is not a comforting thought when you get a "Check Engine" light!
I feel that agonizing over a half second difference in zero to 60 times or lap times is really missing the mark. I live in a rural area with beautiful country lanes where you can cruise along, smell the salt air, and enjoy the scents of woods and flowers, so I really don't care about absolute performance. If I get the 124 Spyder, I'll just enjoy the hell out of it!