We had a post similar to this recently. I think the suggested changes revolved around the following:
1) +1 Toughness (from the mount) - Increases survivability
2) Special Rule that grants Hammer of Wrath at S5 AP3 - makes the initial charge more reasonable (no more 20+ I5, S5, AP3 attacks) and allows them to continue to be an AP3 threat after that first charge
3) Equip them with Power Lances (S4 AP3 on charge, S3 AP4 melee) - slightly reduce effectiveness vs. 3+
sv armies (2x I3 S4 AP3 per charge vs. 2x I5, S5 AP3 once per game), increase effectiveness vs. 4+
sv armies
4) Give Commissars/Priests the option to buy a mount - allow options for synergy and buffing
5) Take away the "one time use only" from the Hunting Lance - doesn't affect their 'glass cannon' usage, but makes them vastly more threatening after initial charge
I quite like the combination of 1, 2, and 4. It would make them slightly more survivable and normalize their melee effectiveness, while giving the option to pay points for Fearless, Zealot, Stubborn, High
Ld, etc. 3 and 5 seem to be too big of an offensive boost to me and I think they do need a slight buff in the defensive department.
DoW