As a test case I did a conversion of an exteriour scene of evermotion… Please tell me what you think about it.
see the webplayer @ http://db.tt/HA2HXkp
Looks great! did you optimize the scene before you put it into Unity?
wow, just wow!!!
it looks very very very good. what program did you used to produce that?
Nice scene, like the design. 
However, you need to optimize the scene alot. (not smooth fps when flying though it. thus less than 24fps, which is the rate in which the eye considers it smoothly moving)
Yeah it was optimised before export to unity. 3dsmax was used.
It could use some lod and occlusion culling to speed things up.
I cannot take credit for the nice models they were made by evermotion
See the origional here
http://static2.evermotion.org/files/model_images/09bd7fd6048a7c3418b9387812b3db18.jpg
Check out my interiour test case here http://forum.unity3d.com/threads/91689-Evermotion-attic-room
It looks quite ugly that backfaces are not rendered. This makes most of your rooms just invisible.
Pool also has artifacts because of that. The border has normals which only allow border to be seen from IN the pool, not out of it.
Other then that, models look nice
Lower the resolution too. Not all of us have 1080p 
i had a shader on it to solve this, but the new version of unity had problems with it. I still need to update it
what technice did you use to optimize the models? Great to know i need furniture. for my house viz