This is something I have not been able to adapt to in Sublime Text. I wish there was an option for mac users to make it behave in the standard way that find dialogs behave in Mac applications.
It wastes so so much of my time. And to add insult to injury, changes to the find field are immediate, so every time I mistakenly think focus will be in the editor and start typing BOOM! I am at some other usually unrelated part of my document.
It's totally muscle memory, from years and years of being a mac user, and I despair at changing it in my brain. And if I did succeed, I wouldn't want to make it muscle memory and therefore FAST because then I'd be screwed in normal mac applications.
I just keep hoping Textmate 2 fixes it's performance issues, because despite the power and flexibility of Sublime it's many little un-mac-like quirks are a constant frustrating drain on my productivity and enjoyment.