On the one hand, because he's been most productive at 5 or 6 I'm inclined to leave him there. On the other hand the top order batsmen are really just not getting it done and as Remie's pointed out the man really seems to be in the form of his life. He's coming in at around the same time as if he'd open or bat at #3 anyway.
It is so disappointing that not ONE of the other batsmen are really digging in to stay with him. It seems like the team concept still isn't with them. It's not about them making runs while he's there, it's about giving him as much strike as possible while ensuring they stick around. If they rotate the strike enough they'll get a few runs themselves.