That seems about standard for Illinois. My experience from recruitment found the professors incredibly affable, and in general, I felt that for the most part they were friendly even afterwards. One nice thing about our department is the professors all treat the grad students with respect, even the grad students from different fields. For instance, one time when I was at the department copier, a senior member of our American faculty came by and wanted to copy something. There was only one working copier at the time, but instead of asking me to get off, he asked me how long it would take, and then asked me to fetch him when I was through. I volunteered to let him go ahead of me (especially because my copies were time consuming) but he replied by saying he was in no rush and just to fetch him when I was done. Keep in mind, he wasn't my advisor, or even a professor in my subfield (he probably doesn't know my name).
From some stories I have heard from other departments, I know something like this is a rarity.