If looking to be in the hobby any length of time, and needing to purchase new batteries... I'd definitely recommend going the LiPo route. LiPo batteries can be had at, or below what it would cost for six cell NiMh pack. The only additional cost would be in a good charger to charge LiPo cells.
I haven't used NiMh packs since like 2009-ish. A few years back, I did try to relive the good old days of RC by buying a brushed motor ESC (
T4.3 thread), and a couple of brushed motors. Let's just say I tried it; it was fun for a few weeks, but sold my brushed stuff and never going down that road again.