a lot of people feel like spears are too powerful, and heavy cav unpowered.

One alternative way to redress the balance is to expand the mount/dismount system (I've never seen it mentioned much, so it' a fair bet it not widely used). Why not be able to dismount DURING THE GAME (with impossibility to remount during the game, though).

If you face large amounts of spears, just dismount and chew them up. It would rebalance a bit the anti spear spectrum of possibilities, with the rock scisor sytem.