Agreed, there are differences in its intensity...

... presumably based on how complete the soul is. I'm also keen to find out if it was everyone who received this newly awakened "gift", as it has implications as to whether everyone could potentially have it awakened. The wording Urianger used, "full many in the crowd", would suggest it's not all, but leaves none the wiser as to the why. Could have something to do with how weakened the cycle of rebirth has left some souls.