MM6/MM2 differences when compared to MM5/MM1:
- works in countries where 2G is switched off since it uses 2G + 3G signals, where as MM5/MM1 only uses 2G
- consumes 30% more energy, so battery lifetime is 3-4 months shorter - so MM5/MM1 has longer battery life.
The reason for that are the below improvements:
1. MM2/MM6 provides more accurate GSM approximate location, which helps a lot when GPS signal is not available (underground garages, GPS signal is jammed and so on);
2. Better chances to get a GSM connection. MM6 covers both, 2G and 3G networks - if the 3G signal is low, it will search for 2G service provider and connect to it (and vice versa).