OK, not meaning to thread-hijack here... But I've heard this "moving air" concept for ages now, and I really want to know what is meant by it.
Is it simply a slight amount of reverb, like is suggested in this thread? Is that the general consensus?
Also (just to add a bit to the discussion rather than only hijacking), when comparing to pro level recordings - remember that you don't know how much processing was added during the mix phase. There might very well have been a good deal of EQ'ing going on.