As you know, When you gain a level, your abilities cooldowns are reset. this can be used to your advantage with the Achon ability. it requires a bit of timing, but makes using this ability while leveling have an added bonus.
When you know you are going to level soon, pop archon, and go to town. ding your level and the Time remaining on Archon is reset, allowing for alot more time in archon form.
using this in the festering woods, i was in archon form almost long enough for the skill to reset, with the 15% reduced cooldown passive skill.