Thanks for the info! I ordered yesterday... Went for almost the same setup as you (mx5, mxc2, mx1, mx1, & ms-400). I hope it's not overkill! Part of the problem is that I don't know what size room they're going to end up in: we're moving from the UK to Oz next month! A lot of Aussie houses are open plan, so I thought they might end up in a fairly open space. On the other hand, some of the new builds have dedicated "home cinema" rooms, which tend to be about 4x4 metres -- which could be a bit of a squeeze for a 7.1 setup?
But I decided I could always move the mx5s out, and one pair of mx1s would be OK as fronts. I wouldn't even need a new amp, as the mx5s are going to be driven by my NAD C326BEE, with the rest driven by a NAD T748. (I'm assuming the C326 will be better for stereo, although I might just compare against the T748 and simplify, if the quality is comparible for music!) And the worst case scenario is that I sell the speakers for a profit (or at least no/little loss): Australian prices are crazy compared to the UK (which is why I'm buying now!).