I have to admit, that sounds like a nice mustang for the money...very good! But I'm also guessing that car had the higher gearing right? That would make it no faster, and probably slower than a V6 Camaro. Of course thats before modding.
You are going to have to decide for yourself....looks or performance?? Which is more important to you? For me...looks is just as, and probably a bit more important, and since the V6 has a good amount of performance and great looks it was my choice! Now if the V6 had came with "just" 250 or whatever horses like many V6ers I may have waited on an SS. If it wasn't for all that weight these V6 camaros would be absolute screamers, but as they sit they are still quick and fun to drive, and even better once you start adding your own touch whether its visual or performance mods.
To me, both the Camaro and Mustang are great cars, so good luck with your decision and hopefully you never have to look back with a lot of regret!
Imagine yourself in both cars, and then the other car pulling up beside you....at that moment would you be thinking
or :(