I just bought the TREK 2014 FX7.6 WSD.
I bought the WDS because I am shorter, have narrow shoulders, and have smaller hands. It didn't seem to matter on this bicycle. Make sure the shifters fit your hands! I had to have mine switched out extra costs) so I could use them. I also did switch out to a wider tire so I could ride on a crushed limestone trails or when it is a little damp out.
It's a long story why I wound up with this bike. If I had the opportunity, which I didn't without losing a lot of money, I would have looked at the Specialized Vita Comp which I think is similar to the FX and comes in a XS.
Don't buy a color you don't like. You will be reminded of this every time you get on the bike!
kajero
2013 Trek FX 7.6 WSD
2012 Specialized Ruby WSD
2004 Schwinn (I think that is the year)