» Wed May 02, 2012 1:41 pm
Perhaps you already have, but if not, I recommend stripping Oblivion back to "pure vanilla" some time (or having a vanilla install, side by side), and keeping an eye on frames per second in different areas, as well as with different numbers and kinds of NPCs, animals, etc. Personally, I found this very informative. For example, some people have mistakenly blamed Better Cities for a dramatic drop in FPS in the Waterfront area of the Imperial City. See what that area does in vanilla, and you will see what I am getting at.
That said, Better Cities is known to have a more significant impact on FPS, generally speaking, than Unique Landscapes. Open Cities Classic does not impact FPS noticeably. Open Cities Reborn might, somewhat, but I am fairly sure that the impact is relatively minor. And not only does that mod provide, well, open cities (a very good thing in itself), but also an interpretation of the original Bethesda concept art for the cities, resulting in the cities being "as they should have been", one might say.