Higher "C" batteries of the same rating weight a bit more.

For instance a

2200mAh 30C pack will weight more than a 2200mAh 20C pack.

A 2200mAh 30C pack produces a theoretical 30 x 22 = 66 amps at peak.

However you can achieve the same thing another way...

A 3300mAh 20C pack produces 33 x 20 = 66 amps at peak.

However the latter may fly a plane drawing 22A far longer and with less wear and tear on the battery packs.
Higher capacity packs ( higher mAh ratings ) also TEND to keep the voltage levels higher. The higher "C" packs compensate by adding more plastic element windings to each cell, increasing the size and weight a bit.


In reality the max "C" rating of a battery should always be used as a MOMENTARY INSTANTANEOUS PEAK rating.

In actual practice you should design your power system to draw about 60% or so of max available current during hard/heavy use, for safety.


All of that said, you have to determine how you want to fly your planes and what works best for you.

2200mAh 20C packs tend to be fairly standard and used on many planes. So the 2200mAh 25C+ packs COULD give you better flexibility, if they fit other planes. Remember that the latter will be a bit larger too.

You can also gang packs together... so from two 2200mAh 20C packs you can make one 2200mAh 20c 22.2v pack or one 11.1v 4400mAh 20C pack.... using nothing more than removable connectors. As such I tend to use the 3200 or 3600mAh 11.1 packs where I can, knowing I can tie two together and fly a .60 sized airframe with the batteries doubled up.