I honestly can't fit the subs in any other location. That's the thing, I want oomph and low end extension, hence the dual 600's. I used to have a single 500 but having duals made for a big improvement.

The M5 I'll get for sure. The subs probably around mid July. I may go to the QS8's instead though. But that can change but it may be much much later this year when I get the surrounds.