Elites all over the plane board first, and this usually fills up all E+ seats except middles. Then all remaining window seat passengers boards, then middle seats, then aisles. It's up to you whether you think it's better to have a window seat in non-E+ or a middle in E+ (which you will have to pay for since you don't have status). Personally, I'd take the window seat because you'll have more bin space and nice views!