I don't play heads up that often. Unlike most counters, I prefer 1, maybe 2 other players for a several reasons. When I do play heads up, I like to set a nice rapid pace. Get through the deck(s) and get to that shoe where their is a nice juicy count and then get out quickly.
Occasionally, not often, but occasionally, I run into a dealer sort of being a dick about the speed thing. They try to go too fast, faster than they can or should deal, in an attempt throw me off. When that happens, I like to turn the tables and intentionally slow them down. It really can annoy them and actually throw them for a loop, to the point they become even sloppier than when they were going faster.
While usually I do this 'slow down' action out of spite, there is a practical side to it. When a dealer is trying to go too fast, they usually start "assuming" my plays, which I don't want. When I finally hit that max bet count that I am looking for, and am doubling and splitting more aggressively, I don't want the dealer, flying past me, assuming I am staying or hitting when I want to double or split.

And the last thing I want is any kind of controversy in this area, where the pit has to be called over and explained anything. Not when I am sitting there "exposed" with my max bet out.