Dimitri, although ATC "silently" designates the 752 as heavy, they still do not call it heavy.  What I mean by silently is that they have a special set of separation minimums for the 752 that are different from large aircraft (less than 255,000lbs, but more than 41,000lbs), however, similar to heavy aircraft, even though the 752 is considered large.  If I really felt like typing this evening, I'd list all the separation distances and minimums, but I don't.   ;)