The efficiency argument isn't really about macro-efficiency, it's about micro-efficiency. It's not, "with my lightning fast editing speed, I will drop 10k lines today", it's about writing this method faster so I can run tests and see if anything changes, getting me to the next thinking step that much quicker while the problem is still fully loaded into my head. It's about keeping flow state flowing. It's about reducing the iteration time between working code states, so your cycle time gets tightened.
IME, without good muscle memory (touch or hybrid typing) of keys, consciously searching for each key is going to seriously disrupt the flow and thought process behind the code being written.
It may not make you a rockstar programmer, but it will definitely make coding more enjoyable.
I think there was a recent HN discussion on this topic.
