1999 and up? there is the new edge gt's that are from 99-04 and then the s197's from 05 and up. if your comparing the New edge to the ws6 dont even think about the gt. goes with a ws6. looks better, performs better and is just as easy to mod. now if your looking into the s197 GT its a different story. imo the interior on the new ones is 10x better then the new edges. thats one thing that drew me to mine. the ws6 will still out perform a S197 GT but the new mustangs have a HUGE aftermarket. personally i like the styling of the new mustangs over a ws6 but im a little biased lol. you cant go wrong either way.