I still think endless.com is better. I just ordered from Zappos for the first time because my beloved endless didn't have a pair of sandals I want.
Endless never charges for shipping, which is lightning fast as well. It is also always free to return.
What really gets me is that I just paid about $12 tax for my Zappos order, which I never have to pay with endless. Since endless is amazon (which I also love, since I just use my amazon account), no tax is ever charged.