It's not really an improvement, it's just a difference. Sealing one side isn't a good thing though as the cables have to be accounted-for, and it blocks air-flow so that also has to be taken into account.Why not cover it from the side to seal off the back? That way one side is completely open (and you can tape if needed) and then cut slots on the other side? I got that idea from an Larry Mitchell post
Personally, I'd not put myself into that situation.