I did the upgraded pigtail as well and went from 1:30-2:00 flight times (with 14000kv fast motors) to about 3:30 flight times! It has something to do with the actual connector itself. For some reason, when the motors draw out a lot of amps, the stock connector "bottle necks" the higher current flowing through it. (Probably a weird design, probably wasn't designed for high amperage discharge). The awg of the upgraded connector is the same if not a little bit thinner, which is pretty weird. (Without the upgraded pigtails, it never discharged my battery all the way! I checked with a voltage meter and it allways went from 4.2 to 3.9. Now it goes to 3.7v!)
I have learned that if you do the insane motors or anything higher than The 14000kv fast motors, you need to do the LVC mod or you will get 15s flights because of the amp draw.
Hope this helps!
sorry not true about the motors for everyone...i upgraded the motors on my inductrix to 18,000kv with no problems at all. That plus the upgraded pigtail with 205-210 batteries gives me an honest 3 mins 45 sec's of flight time with the camera running. It is luck of the draw sometimes with these and their boards. Some run great (like mine) some do not. The E010'S seem to be more flakey than the Inductrix (higher quality boards and all)