^What Mando said.

Plus, if you lose initiative, and you don't win combat in a round, you have to deal with a second set of attacks. If you win initiative, you have a second round of attacks to disable the opposition before they can attack again.

As a PC, it adds up. If you go through the recommended 4 a day, if you win all four times and clean up in two rounds, you've saved yourself 4 rounds of damage and healing. If you lost those four initiatives, and still won in 2 rounds, you've taken an extra four rounds of attacks. This may mean you blow all your healing for the day, or worse.

Honestly, if your going for balance, I'd almost have to say Weapon Focus. It helps everyone in the same way. WF(Ray) or WF(Greatsword) both improve the ability to hit with them.