after pitting the bearings in tons of cheapo loose ball headsets and having to replace them when the indexing got too bad for me to stand; i now just try to find the cheapest headsets that have replaceable cartridge bearings.

on a roadbike i doubt you'd ever kill one but offroad they sometimes crap out; if you have replaceable bearings swapping them is super painless. problem with this is; the replacement bearings often cost more than a new headset. if you can install your own headset; deals are easy to find.