I currently have a set up which includes a MCU, 2 XT and a C4.  I would like to add one more XT for a total of 32 flying faders and also a M-audio trigger finger.  Can Sonar handle this many controllers?  What is the maximum?  Thanks

The fact that sonar provides limited tracks should not be a problem for the MCU,it should see just as many tracks as sonar can throw at it.i'm planning the same setup my self with the Mackie MCU,if you have 40 tracks in sonar you can move from one bank or tracks to the other using the WAI display in tracks view (Where Am I display) and in the console view also.

I think only CW or some user with so many controllers can give definitive answer. From what I know about CS API and MC plug-ins, there is no strict limitations. But there is additional (continuous) load on the system because of the framework design once you add controllers, which potentially can influence latency/stability on particular system.