I think if you ask 10 people this you will get 10 answers.
I pretty much do the same thing using two servers. I mostly have two servers so that if one goes down I still have stuff up, that and I get a good deal.
From what I understand no one seems to know for sure what benefit if any there is having domains spread across hosts as far as SE traffic goes.
BTW: I'm also with M3 Server and very happy.
