Although both use identical active ingredients, Micropur has three times the potency of Aqua Mira. Micropur is EPA registered and is allowed to advertise effectiveness against bacteria, protozoa (crypto, etc.) and viruses. AM is not EPA registered and mentions only treatment against bacteria (forbidden to mention effectiveness against the other two classes of baddies).
Treatment time for Micropur:
Bacteria and viruses -- 15 minutes regardless of water temp.
Protozoa - 30 minutes (room temp) -- all the way to 4 hours(!) if water is just about at freezing.