attachMvoe or loadMovie

Hi,

Is there any differnce in using the attachMovie instead of the loadMovie (preformance/loading etc etc)

I have 3 section in my swf (main): home, about us and contact. So when I click the about us button I want to attach the about_us mc in the main_mc. I always used the loadMovie to load external swf but this time around I want to use the attachMovie (ofcourse this time I use MC insead of swf that are included in the main.swf libary)

Is there any differnce/(dis)advantages using attachMovie over the loadMovie??