Going from 1500mAh to today's NiMH batteries is like night and day.

Do you need a stick pack or flat-pack?

stick:

flat:

I've started to move over to the enerG 4600 mAh cells. Got 'em from www.promatchracing.com at $5.50 each cell. They will build up packs for you too - you probably will just do fine with sport packs, not their matched packs. They maintain higher voltage over the course of using them vs. some other cells I'm using - and the results on a track are visible.