Hi webwringler,
Going MPPT is similar to any other decision made about a solar system.
If you want every last watt and have no more room on the roof, MPPT may get you there. If you don't then a good quality PWM controller with adjustable voltage set points and a battery temperature sensor, may be a better choice.
Handy is/was a Morningstar fan and the controller he loved was twice the price of the Xantrex c-35.
So his advice needs to be taken with a LARGE grain of salt, for it is not terribly useful. You need to be quite knowledgeable about what to accept from him and what is chaff. So it is no place for a beginner.
In 2005 going MPPT with 200 watts of solar was a no brainer because cost per watt for panels was $5.50. That is why I have MPPT with 256 watts.
webwrangler wrote:
But he does debunk the belief that you need an MPPT controller for 250 watts in an RV.