This is like saying "the longer a NM is up the better then drop %"! Thanks I'll pass... in the 10min you wait for that 1 kill to give you +100 more exp another player can kill 5 fresh spawned mobs... and going by your example it will be 600 vs 2500 for a 10min period. That is a huge gap. Even if you do find a mob alive for 3h's and get 1000 for that kill at a rate of 1 kill per 2 min, the person hunting fresh spawns at 500 a kill will be a 45,000. Or find 45 mobs which have been alive for +3h's to equate... This is pointless to the point of why bother...