I just had it really bad on a couple of semi large postscript files. It would process fully, then sit...and sit....and sit.... extra minute or two .then whiiiiiririrrrrrrrrr goes the igen.
depends on how much different info is in the files I think. like paper type,coating,color... and maybe caching with variable data. I try to send all my files with as little info as I can. I do most of my own programming.... output setup at least. then make changes to queues. I feel like I am kind of an anomaly in that respect though. But I prefer it this way.