HCC, I think it's a must. If you have 3 cells and 2 are at 3.7 volt and 1 at 4.0 volt, you have the chance of over charging that one cell and ruining it or causing a fire.

If they are not far off and you balance them you would have better proformance out of them just beacuse all cells would be equal. Again 2 cells at 3.7 and one at 4.0 when the esc sees the overall voltage drop to 9.0 volts for a 3 cell it would be sooner because 2 cells were dropping faster than if they were equal.

If all 3 cells were balanced and charged to 4.2, your voltage will hold longer and this increases your run time.
Why not get the most out of what you paid for. Not only that, the way I see it, it's like a small tune-up for a car-keeps it running clean and smooth. BG