If it needs weight to give it momentium to fly right either your setups are lacking or the style of flying needs to modified.

You should bear in mind that with increased capacity also comes increased power. If you are right on the limits of a pack's C rating then it will not deliver as well as one that's comfortably within it's C rating, so it's a constant juggle to find the sweet spot of the heli, mah is not all about length of flights. This is a fact.
You can't go judging things on just stats such as weight etc, actually flying it is the test. Have you done that test?
I don't remember anyone reccomending the 4200 MAh packs ?
"Yep, the 4200's are my favourite pack for the Trex 500, I think the little extra weight that the packs offer is great for improving the characteristics of the machine"
You are now saying the pack is to heavy...
Trev
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