Sounds like my setup. I use 3s x 2 A123 packs to make a 6s pack. 10 min charge times 15 min runs. with a BKWarrior and 9xl. I am happy with performance.
The 3s packs work great in my combat airplane also :)
Highflier
I don't think a 10xl would be pushing the mamba too hard. In fact that might be sort of a light load. I am running my 10+ lbs truck on a 9xl motor and a mamba max. I do have a fan on the mamba but it never gets over 120 now. Nice run area makes me want keep my truck!