if you check closely, those pila 300/600 batteries are not the same as 18650.
18650 is 3.7V~4.2V, the pila 300 is 4.5V, pila 600 is 6V.
18650 is the same diameter as CR123A, and they give the same voltage, but they're not the same height.
the digital charges faster than the trust fire, except you're limited to 18650 batterys. if you want to charge other sizes, trustfire is good. but for 18650 only the digital is much better.
The Pila definitely will charge 18650 batteries correctly. The Pila 600 is NOT 6V. The charger designed for it only charges to 4.2V. I think the pic at flashlightz.com was simply comparing the compatibility of their pila battery with most lights (since a 600 will fit in a light that accepts two cr123 bats).
Overview of the charger:
http://www.candlepowerforums.com/vb/...d.php?t=188653
http://www.candlepowerforums.com/vb/...d.php?t=201323
None of the protected 18650 batteries are actually "18650" batteries. They are both wider and longer than unprotected batteries but generally fit in the newer flashlights that accept protected cells.