RE: Li-iPo Batteries
The 20 amp will be more that enough for the 3c 1200 packs since they are rated to only put out 3.6 amps continuos. You would ruin the battery well before burning out the speed control. The 1500 pack even if they are the high discharge type will most likey only be capable of 15 amps at 10c so once again the 20 amp controller will be more than adequate. Keep in mind on the 1500 packs that the gear box and prop will be the determining factor for the amp draw. I guess this was just a long winded way to say the 20 amp speed controller will be fine.