Reply to DIY midi launchpad/mixer

So for a wile now i have been Djing using traktor with a novation launch pad for basic 4 deck control and a analog mixer for mixing along with a couple other midi controller for traktor's other functions. I love the 64x64 button grid the launch pad offers and was believeing it would be a lot of fun to create my own type of DIY launch pad/mixer midi device using arcade buttons for added cue point juggling button smashing goodness. Here is my design so far.



So the buttons are separated into four 4x4 squares, each one controlling a different deck.

I am just looking for any feed back from anyone on things i left out, things i should add, things i should take out, layout changes, basically any thoughts or suggestions. Thanks for the help!