Yes, I added it this morning... just for something different. Although, it is growing on me as I spend time in it today. I've almost always used vB 3.x - Fluid style, as well. But, I wanted an extra option for people who don't use that and don't like the plain default XenForo style.
I am seriously considering making it the guest default. The standard XenForo style (which is the current default) is not very appealing. This is definitely better than that. Of course, this won't effect those who use of vB 3.x - Fluid, since that isn't the default anyway. People can still choose the vBulletin style, and have it locked it into their profile options, if they prefer.
I prefer the Flat_Awesome style over the current XenoForo style. The interface is more user friendly/clean and the font size is way better on the eyes. I would love seeing this as the guest default.
The Flat_Awesome is certainly clean but I've never taken to the 'flat' concept. I would think a newcomer/guest might have some initial difficulty in navigating the forum. Enough to scare them off? The depth in the traditional design makes for intuitive navigation. Form follows function. The perceived separation of the elements is easier on the eye, especially for those with older and/or impaired ones.
Look's better than before, but not as good as the original one a year or two ago. Who cares is the question?