Kalam! It should be... but right now, wearing only a white tunic with mail, mail chausses, no helmet, no gloves, heavy lance, Steel Pick backup, and heirloomed Norman shield - I cannot make money on a Sarranid. I can play about 5 rounds before I'm down several thousand gold and have to go Pilgrim Robe peasant again...
Huey, I'm glad you made a thread, man. I've been feeling the same way.
- Horse Charge was OP and needed a nerf.
- Armored Cav was OP (because of Horse Charge + armor) and needed a nerf.
- Light Cav was never a problem. Look at one angrily and it will drop dead. Working as intended.
- The cost of Light Cav needs to be lowered.
Strength   18   
Agility   20   
One Handed   1   [1 WPF cost]
Two Handed   130   [7 WPF cost]
Polearm   24   [1 WPF cost]
Archery   1   [1 WPF cost]
Crossbow   100   [5 WPF cost]
Throwing   1   [1 WPF cost]
Ironflesh   0   
Power Strike   6   
Shield   4   
Athletics   6   
Riding   3   
Horse Archery   0   
Power Draw   0   
Power Throw   0   
Weapon master *   6   
As you can see, my character is a super hybrid 

 I ride horses.( Palfry, and Rouncy). I use Heraldic mail, Red wisby, Mail Chausus, and kettle helm. I always have a great axe equiped. When I ride horsey, I equip my light xbow, and my lance. Cost: 32k More than effecient enough to make even on X1/X2 games and effective enough to make money at higher multipliers. 
With the High(er) agility and a tad smidgen in polearms, i can lance effeciently on horseback(and even use polearms on foot fairly well). I can also be fairly accurate with my xbow while riding even when i have no HA, due to wpf and my own understanding of how xbows fire when "wide reticuled". 
Problem: I get cockey or stop paying attention, I'm usually dead once that happens. My success as this horse xbow is entirely dependent on map and teams. 
Therefore: Cavalry, if built right, and played right will always be effective.