I've never seen this lag either. From what I understand, it's a localized issue (ie: your computer is doing it, not the server) caused by crappy PCs (

), and it comes about mostly because of the lousy engine's handling of complex interiors. When you have the Titans near each other, suddenly it's drawing both interiors at the same time and overloads graphically. Or something. I don't know, never seen it.