Yeah the bang for your buck is pretty awesome with this car. But as Team Plutonium says, the fit/finish and interior are garbage/terrible and I completely agree.
It takes nearly $20K in mods to put the M3 to get it to perform similarly in a straight line + braking performance. $12K Stg 2 SC, $2K mid-pipe/cat delete and $5K BBK and a bit for camber plates and maybe tires. Stock suspension of the M3 is good enough.
After that, you have a 650+ HP M3 with a much different power delivery than the Ford. Torque is no longer lacking, but it's still down 200 comparatively but revs all the way to 8,400 RPM, something the Ford could never do.
With this package, handling hasn't changed much, but is probably good enough to keep pace with the Ford. Plus you are doing it in way more style...but without a warranty. For quite a bit more $$.
Just my worthless 2cents.