25C vs 30C

the flightpower packs are rated pretty correctly. So the 30c will have more discharge capability than the 25c pack. The math is fairly simple. Use a 5Ah pack for example,

5 x 30 = 150

5 x 25 = 125

So as you can see, the 5000mAh 30c pack has a continuous discharge of 150 amps. The 25c pack has a 125a discharge. You don't really need the 30c pack if the 25c pack can handle the amperage your setup will be pulling. Of course, the extra headroom on the 30c pack will always be nice, providing the extra cost isn't an issue. As far as performance comparisons, the two packs should perform equally, given that the max continuous amp draw is below the limit of the 25c pack.

J.