The point was that you can use one (mana returns) to get you in the neighborhood of the other. I mentioned both because the timers are linked. (Or expressed another way, there is only one timer: half the time with two effects [exp & mana both], half with just one [only exp].)
Mana used to be "every two minutes", period. Experience was one minute into the cycle. This was entirely too reliable, and saw things like people scurrying through a hunting ground to be on a local Node to catch the mana, then running back out to kill things. Too powerful.
Now it's variable, but only so far (up to as much as +30s). But the experience-only pulse is the one that is variable; the mana always comes 60s after it.
(And naturally, you can't rely on either one of them if you have none of it to happen. If you have no field experience, you can't use the just-experience pulse to tell you when the mana pulse is only 60s away; if you have full mana, you cannot use the mana-plus-experience pulse to tell you when the clock starts for the experience-only one.)
