First, i like your logo setup, really a good idea, and well done!
For the bad critics, keep in mind that i say them knowing my own www is really poor
First, as others said, the viewing is not good, renders are way too small, and should directly open at a bigger size (so that you can put off the 2 links enlarge/close)
You should name them, it's easier for a customer that want a result like in the render "xxxxxx" for example
You shouldn't mix archviz and products renders
I wouldn't show the actually second render, i think you want to show the model and not necesseraly a nice render, but we actually don't see details because of the small picture size, so it becomes a bad render
In the 3th, i'll add reflections in windows, especially in black areas
In the 4th, i'll add grass or table wood on top of render, the scene floats in space
In the 6th, i'll make people semi transparent, not that they hide parts of the project, but for me they're too much eye-attractive
In the 7th, i'll do nothing (!) but move it at the first position, just that it's impressive!
As a 3D man, it was nice to see the big version of your logo, but i wouldn't put it that way for several reasons , maybe you could put it in the background, or make it the first thing customers see before surfing in your project (or something like that)
In the "about us" section, i'll write "3D architectural" or "three dimensional architectural" cause the 3 is actually alone, it's hard to read and strange
And one day, maybe i'll take time to apply all those good advices on my own
and obviously your page doesn't fit to a large company.