What are the formulas to use when determing a brushless setup?

[lincpimp]

I would say that a higher c rated pack will not drop voltage as much under load (even if the lower c rated pack can handle the load) and you will notice better performance. Not sure if runtimes will be better, but battery cycle life will be better (if both packs have similar cycle life to start with).

Using the best performing battery you can find that fits the size/weight requirements is always a good idea. I just picked up a 6s 5000mah 40c zippy from HC, and will be interested to see how it does. If it can power my big 6s trucks as well as the flightpower 4500 30c (it should) then I will be a happy camper! It is a bit big for the muggy, but should fit the lst fine. Which is good as I only have 1 4500 6s pack since I sold you the 2 4500 3s packs!