Even when you “turn off chat”, chat is still on and still logs in every time you get into gmail, even though it shows you as offline. with it turned on, you can watch it as it logs you in and sets your status. And with it turned off, you can still watch it go through the same exact routine of logging in but setting your status to offline.
If you try to do anything at all during this time, such as open an email, it will wait for chat to finish logging in before responding. It is really annoying to have to wait that extra time considering I told it to be turned off.
Those browsers that have an extension to hide the chat pane will not circumvent it in any way… it will simply load in the background and you’ll still have to wait while it does that, even if you can’t see it.