I am obsessed with efficiency. No matter what task I do, my mind immediately seeks the most efficient way to get it done. Efficiency can be funny, though. If you spend an hour trying to figure out how to shave 10 minutes off of getting a task done, then you have been incredibly inefficient (assuming you don't do the task 7 times or more).
When it comes to writing, though, I've discovered that there is a limit to how efficient you can be.
Consider the time it takes as a writer to put down your thoughts. You will either use a lot of words or a lot of time. The former is more like a stream of consciousness, saying whatever comes to mind, potentially taking tangents as they arise, and continuing on until you exhaust your supply of thoughts. The latter is carefully crafting your sentences to perfectly encompass everything you want to say and present it in an easily digested manner, which will need few words, but much time to create.
The same ends up being true for reading. If you have to read a stream of words, then it will take a lot of time to get through them all; it may not be deep, but it's long. When you read more succinct words, it takes longer to process everything that may be contained within those words; you may have to read it multiple times to get it all.
Ultimately, there reaches a point where you just can't go faster. When you get there, quit worrying about efficiency and just worry about writing the best damn thing you can.