We made a simple change that has made parry more popular. Basically, a successful parry does not use your reaction. One on one it allows you to defend yourself against multiple attacks (Lightning attack etc.) and gives you a reason to use parry rather than Dodge. A failed parry uses your reaction (explained by the interruption you would have by being struck by a blow).

This has made for more entertaining fights, and has encouraged our Marines to get into the thick of the fighting where Marines are supposed to excel.

That is an interesting rule. I might try it out in my game.