I mentioned the butterfly dome somewhere on this forum, but haven't seen anyone else mention it. You enter it through the gazebo. It's really worth checking out, and would be great for building, too, except that it requires a flat 64x64 lot.
Wait, I'm ditching the junkyards since the patch, so I can use that space to place butterfly domes.
LlamaMama, I've checked it few times now, first time it was new game and no butterflies were spawned jet, but after a while they did and it is beautiful. I also like that flower arrangement in shape of butterfly:) I found special seed in it too, so it is definitely worth checking out, and it would be really eco-friendly to replace junkyard with it
I checked around web about city inspiration, and it seems that one group agreed with me about combo of SF and LA, while other agreed with Pam and Crimson, comparing it to NY and Dallas:) I Still I think it's the Rocky Mountains in background, and West Coast because of that broken road and crack in the ground. And probably as Pam said, combination of many large cities around USA which look alike.
As for the apartments and comparison Sims 2 vs Sims 3, it is pretty pointless. It is crazy to think about 30 apartments on one lot, but nice expensive penthouse with few small cheap apartments on lower floors is doable. My dynasty has a home with 9 bedrooms, 10 bathrooms, 3 reception rooms etc and it loads just fine. Also, there is no loading screen but there is still loading time. You can see only lower quality 3D images of everything around town, but it takes to zoom in and wait a while to get a better detailed view. And even then you can't see inside if your Sim is not there. So technically it is doable, but it is really pointless to discuss it here, I think.