Hey Chuck,
No, I didn't mess with the buffer size. 
If I do clip FX, I'll commit to sound by bouncing to clip to reduce CPU taxing.  I do run effects in the FX bin as I mix while looping though, and change parameters with the plug on the fly.
With 32gig of RAM I barely touch the CPU even with high track counts.
Thanks for the input.  I appreciate it.
Mark.