I think magento 1.5.1 out of the box with the fooman speedster module and a few tweeks to the htaccess page works well.
Sorry but I think www.fierceshades.com is slow, I am not trying to be rude but it is just not that fast for me and when I checked YSlow they agree with me, not sure if that was the best example .
I am in the middle of designing a new website and like I said in the beginning we have done nothing to improve the speed other than what I said above, its on a shared server with simple helix and IMHO the site is pretty dam fast. after the first load most pages load under 1.5s and the home pages loads for me under 1s, that’s not saying that it would not take long else where in the world.
Yslow reports that the home page is rated A with an overall performance of 94, category is grade A with overall 93 and product page is grade A with 92 overall, so for a site out of the box with just the foomans speedster its not to shabby.
I know the site does not have many products but can not see why its would slow down that much once we start adding them.
I have been using magento for a couple of yrs and I agree that in the beginning it was painfully slow, but with every upgrade its getting quicker and quicker, and I have tested a few other ecommerce software and there is little between them today.
Hope that helps..