Reply to "Beginner question: Can one transformer do it all or do I need different brands?"

I started into command with a single Z4000.  I stayed using one transformer until I got over 8 amps per side.  I then split it into two Z4000s with the goal of trying to keep the amps between 7 and 8 (with smoke on and 40 smph).  I now use 3 Z4000's, 1 Pure (something), 2 180 bricks, 1 Z1000 brick for track power, and one Z1000  with the variable voltage for operating accessories.