One key factor for a better user experience.

What is the top factor in creating a better user experience?

I was reading through the 'Usability Study: Men Need Speed' talking about gender differences in web.  While the study's sampling size is small, 'Ease of Use' trumps Download Speed, Navigation, Accessibility, and Customization for both men and women.

I found this interesting as it conflicts with what I feel is an almost natural tendency for website owners to request more and more features. (Can we add multiple ship-tos, multiple payment methods, and a few more options inside the checkout process - or perhaps we should just make it really simple and easy to use)