I tried 3s and was happy with it with running 8400mah packs - I listened to god aka brian and went to 4s and WHAT a difference - Didn't stop grinning... You can pick up a 4s 5000mah 25c for $125 and you are off....
http://s168.photobucket.com/albums/u...urrent=018.flv
MM has a 4s cutoff you just need to buy an UBEC - Mike has some good ones or BPP has the new castle one as a backup...
I run 24/65 at the moment but will drop back to 22/65 now I have 4s... Will also be trying a few test runs on dual MM dual 9XL on 22/65 soon...