[latchkey]

With LR, I actually had to un-train myself from constantly reloading the browser window. Now I just save a file in my IDE, and LR does it for me. I couldn't imagine going back to anything else.

[rimantas]

And in case of CSS LR does not even reload the page, it injects CSS. Very handy for styling some "in between" elements—popovers and stuff like that.