[ramjam]

I do not think that the question admits of a correct answer.

I imagine that maximizing your hourly rate would involve giving your full attention to the actions of the other players (on both that and any other tables you are playing). Therefore, playing a short stack(s) whose size requires constant monitoring and frequent reloading seems an unnecessary distraction.

There are also psychological and image factors to consider. Small stacks can look weak and desparate. A very large stack can suggest a serious player stepping down in limits (whose bets are to be respected), a player with an ego problem who wants to be respected and/or a generally loose approach to cash. An average stack tends to blend into the crowd. I wouldn't pretend to be able to understand which of these images offers the most bang for your table buck.