[washy]

I had exactly this dilemma. In fact I passed up on an M4 at launch just to see what the M2 would be like. Unfortunately what I should have done was put a deposit down at that time for the M2 as when I started to seriously think about it I soon realaised that here in the UK I would be unlikely to get hold of one until next year.
So I have ordered an M4, but still think the M2 will be an epic car and look forward to seeing tham out on the roads.
Had availability not been an issue I could have still been tempted either way as I love the power, seats and extra comfort of the M3/M4, but do think the M2 is just about a perfect size.