I ended up winning/getting a Topeak Mini DX pump last Christmas during an office gift exchange party. I recently had to use it and found it to be a real pain. Even though it is dual action (pumps on the down and up stroke), the travel is so short that I looked like an adolescent chimp discovering his body for the first time. I have another no name pump that has a longer travel but with single action that I find better.
So, my recommendation is to avoid the really short travel pumps and go for the longer ones. Now these Morphs are starting to look really tempting but I'll just dig out my older pump and put it into my Camelbak.