credence, You are the man. [8D][X(][8D] Thank you for the great info.... I have a few more questions if you dont mind. & please correct my calculations if they are just plain wrong. Mainly I am not sure but it seems to me that a 2200mAh batt @ 11.1v has a total of 24.4 stored watts.... I am assuming I have this correct and based on this assumtion I figured the following:

Ok Im looking at TP batt specs here. Which are as follows for the 2200mAh packs.
2200 @ 11.1V weighs 170g & the 2200 @ 14.8v weighs 218g.
If 2.2ah*11.1v= 24.4w & 2.2*14.8= 32.6w
Then 170g/24.4w= 7grams per watt for the 3s
& 218g/32.6w= 6.7grams per watt for the 4s

I figure the extra 48grams is about 5-6% weight gain for the average 750g 450 heli. While the extra 8watt gain is about 33% added power to the 3s pack.

So again I am confused if people can add 6% weight and gain 33% power why arent they. can the motor not handle the extra rpms?....
Why are more people not flying the 4s packs. Is this just too much extra weight? Or just too much extra for some people (extreeme 3D'ers)
I am very confused. I would like to invest in about 5 batts this week & unless I am totally missing something it seems like a no brainer to fly 4s packs.

Also, is one a more efficient setup than the other?
Anyone out there flying 4s packs please let me know what you think.

Thank You, Noah