I find out that new tech tree actually nerf the bonus for Empire cavalry and artillery. The previous tech tree gives Empire melee cav 5 melee attack and defence, 5 morale and armor, 5% speed, 10% weapon strength, 10 charge, and vigour loss reduction. The new tech tree gives cavalry 10% less weapon strength, 5% less speed and 1 less melee attack and defence. Firing Drills previously provide 20% ammunition and 15% reload time reduction for artillery and now it is only 8% reload time reduction. Some may say Empire is given new techs that target certain races in return, but they won't work against all races.
If you compare Empire's tech tree to Bretonnia's, Bretonnia is obviously the winner. I thought the patch was supposed to enhance empire not nerf it.