Slightly? you're talking more than double in a lot of these cases. Furthermore, not all of them had a variance either.
Toss in the comparatively rare instances where this server comes up with mobs spawned and you're only lying to yourself.
http://everquest.allakhazam.com/wiki/EQ:Respawn_Timers
again, not even close. The only 2 remotely close are nag/vox, and we know the bigger change that affects those 2.
With the amount of patch days the spawns were never too far away from each other. Mobilizing/tracking was a better option then sitting there for 12 hours.