I saw them 4 times, all in the late 70s, early 80s. Once about 6 rows back, center stage. I commented on your Best Performance thread about them playing Tie Your Mother Down, it was absolutely magical!!
They are just seemed so in tune with each other. I liked the fact that the whole band knew Freddie was the star of the concert, and he would rock the whole show. I have a few of their live DVDs, and watch them a few times a year.