Originally Posted by FlashDriveDT
Bottom placement doesn't work for me as GA does not record then.
Yes it does, unless you have frames or something odd that prevents it from tracking correctly.
However, since the code isn't in the HEAD section of the code, your visitors can move around your site before the GA code has finished executing (thus not tracking). Google actually recommends that you stick the tracking code at the bottom of your page.
A1ien51 got it right - since you're waiting for a response from the Google server, your loading time is dependent on (1) your visitors internet speed, and (2) Google's current bandwidth. You'll encounter this with any JS-based analytics tool, so if this issue is critical then just install a server log-based application. Google Analytics is far from perfect, but I think it's an awesome tool considering it's free.
As smart as those people at Google seem to be, I've also noticed that in a lot of their APIs (Analytics, AdSense, and Maps to be specific) they use a gazillion global variables rather than creating a single Google namespace object. While this wouldn't slow anything down, it does lead me to believe that their code isn't engineered as well as it could be or that it simply hasn't been optimized. As a result, the files might be bloated and take longer to download.
Of course I don't work at Google, so maybe I'm just missing something.