You're getting a better warranty and the ability to send it for repair if you have issues. You get a better manual, a programming and operation experience that has been improved based on the feedback of the ham community over every model of radio they've produced. The programming software is often better for established brands (although there's third party software for the Wouxun portables that isn't half bad). You probably get a better front end, meaning better sensitivity especially in RF noisy areas, as well as cleaner filters, meaning cleaner transmit and receive signals.
I've used a Wouxun and a Yaesu side by side. I'm always afraid I'll break the Yaesu because it costs that much more. They're both pretty sturdy. The Wouxun menu is limited (six character display vs Yaesu's full LCD screen), the Yaesu has more features including wide band receive and 220MHz coverage. The Yaesu is much more comfortable to field program once you get the hang of it, whereas the Wouxun can't even have its scan list programmed in the field.