JBJ Viper K-2 bulbs

I have been running two of these lights for almost six months now. I know that MH bulbs should be changed every 8 to 12 months. I also know the bulbs that come stocked in the lights arent the best bulbs either. Should i be looking to replace the bulbs soon? They look ok but i have an XM 20,000k and a Hamilton Technology True 20,000k bulb just waiting for the day when i decide to change them. Plus im anxious to see how the new bulbs make my tank look>;D

 

XM has been good for me.