I do have a problem (perhaps I'm not the only one) with excessive lag inside some cities and espacially IC Waterfront (in some places unplayable). But my impression is that it might be those huge city walls textures and/or building walls textures. So maybe it would be a good idea to replace them with say - Wiseman's reduced textures http://oblivion.nexusmods.com/mods/6446//? and http://oblivion.nexusmods.com/mods/6447//? and http://oblivion.nexusmods.com/mods/6448//? or some others? The problem is - witch texures exactly? An answer to this might make our Oblivion life a lot easier...