Urbo73, very well thought out post. I am a very average driver at the track and my Porsche Cayman is a great track car in that it can make an average driver look good.
As you emphasized, the M3 is a great daily driver but does carry some weight.
When I was looking to replace my 335i, I intended to get a 2010 M3 coupe but faced with a close to $1,000 lease payment I decided to shop around. I then test drove the Cayman and got a great deal on it so I became a Porsche owner. The 911 Carrera S that I liked was about $115,000 and I ended getting my Cayman S for about $70,000.
As I think more about it, the Cayman, M3 and of course the 911 are all great cars. If you own one, consider yourself fortunate.
Former car: 2007 335i. JB3