While I welcome the terrain bottlenecks and reduced levies (in my Venice game, for which none of you guys replied - SHAMEFUR DISPRAY, I got a pink Muslim super empre encompassing literally 1/3 of the known world) the reduced levies will mean an even greater importance of retinues.

It does reduce the benefit of non-holy war expansion into other culture groups however. No particular point in conquering Italy as the ERE since those Italians will hate your guts and won't provide armies.