The military compass has many things going for it that other compasses don't. It is very robust. The metal casing protects the compass when not in use. The tritium allows the compass to be used at night and it is supposed to stay good for fifteen years. It is a dry compass which in my opinion is the only way to go. Every Brunton or silva I have owned have failed because of a bubble that form in the liquid. It does lack a protractor and measurements for some scales of maps, so you would want to add a a protractor.

As far as difference between companies. There both made to the military's specifications. They both are built out of the same materials, so as long as there both brand new there shouldn't be any problems.

I have no clue how accurate the two compasses are, or whether they have global needle or not.