I like most things about the shot, but if you want something to work on: think about light falloff. The people in the front are strongly lit, but the people in the back are much darker. If you move your lights back, and shoot at a higher power, the relative distance of front row -> flash :: back row -> flash will be closer to 1:1, so they'll be more evenly lit.
Otherwise, it's a great looking group shot- which isn't easy to pull off!
thanks had some more time and you are absolutely right, replaced it now with this edit: