Don't you usually get a high, floating deep return after you serve? That would be how most 4.5's would handle returning a top of the head high kicker serve.
That ball is signature material for you coming to net and pummelling the first volley into a corner for a clean winner.
And yes, lots of very good players have problems moving forwards into the transition all court game. Guys like Querry, Isner, DelPo, Berdyck, all look a little out of sorts moving in behind approach shots, as did Roddick.
Just another avenue to explore on your way to 5.5.