Tonopah -
I am an electrical engineer, and I also went through a time when I was really interested in solar power. I investigated MPPT from an engineering perspective (not "does it work?", but "how does it work and why does it work?") If I recall correctly, MPPT is real and it works, and it can get maybe 15% more power from your panels. But this isn't worthwhile on small solar installations because MPPT is expensive. For example, if you have a 100 watt system, it may produce 15 extra watts - but it would be cheaper to buy an extra 15-watt panel than to buy MPPT capablity for your controller. On the other hand, if you have a 1000 watt system, the MPPT (which produces an extra 150 watts) is less expensive than an extra 150-watt panel. Does that make sense?
So for TM use, the answer is probably no, don't buy MPPT. Get a good PWM controller and be done with it.
There is some real good information available on the Arizona Wind-Sun website. They sell both kinds of controllers, so they are reasonably unbiased. Try
http://www.windsun.com/ChargeControls/ChargeCont.htm and
http://www.windsun.com/ChargeControls/MPPT.htm .
Bill