It now has a few textures, a lot of new geometry (approximately 4.5 millions triangles), and the viewer is now using occlusion culling (with hardware occlusion queries) and level-of-detail to reduce the polycount. There are still some places where the polycount is in the 500k to 1 million polys range, but overall LOD saves from 30 to 60% polygons.
I've now got a different problem: memory usage. Because of the increase of the complexity, plus the addition of LOD (all possible index arrays are kept in memory), it uses around 1.4 Gb of RAM. I think it will still run well with 1 Gb and virtual memory, but any machine with less than 1 Gb will probably have a lot of troubles to run it. This is for the full version, obviously; the demo version should be less than that, and run well on 512 Mb computers. All of that to say that i should add some "streaming" on my TODO list in the future.