I myself between m3 and c63 amg !
When the time comes Ill drive them and make my choice..
In my opinion M3 is a great looker if you do some mods...stock exhaust is quite,but you can do exhaust mod for £170 and it will sound as good as replacement for £2000...Biggest problem is throttle actuators,but believe they can be fixed by some people for the third of replacement..Never drove one ,but people on m3 forum who went from manual to DCT saying its night and day!