max cpu stats : 1 versions : user : stats 1.7.3 : 15 people : 0.6~0.9 1.8 : 2 people : 1 .... This is bukkit problem? If it's not. My server need to upgrade..? How about you?
Im afraid its not bukkit's fault. The memory leak/lag is also insane on vanilla but i guess (HOPE) 1.8.1 is in the works
Different 1.7 and 1.8 is using map. But never happened to current state before until released 1.8 even 1.5, 1.6, 1.7.