The only thing I might change is I like to have a little tray of sorts in between the baffles before the return pump. I like to throw filter floss in there to keep anything from getting into the return pump section. I've seen guys make them out of egg crate. I have a refugium though and that's the main reason I like having it. In your setup, not much could get through to the return pump.
I really can't find anything else in your design I would personally change. It looks really good.