hmm imo 5 secounds loadtime are ok.
can you describe what you mean by "lag"?
does the rotation of the player model is sometimes hang?
or is the scrolling through the skins too laggy?
or does the pageload takes too long?
if the player model is hanging may it helps a look at the fps:
click settings and then click "show/hide Stats" on my laptop its between 11 and 59.
sometimes it hangs, but this is may just because the 1.6.0-dev version
also the whole page has enough code that can optimized im working on it!