I think this is more of an audience perception thing than actual changes in Rush. Occasionally I pull out and listen to one of the tapes I made of his program in the '91 to '92 time frame - and Rush is still Rush.
Audience jading, maturing , and exposure to FR et al, however, cannot be overlooked as factor in one losing a bit of his 'taste' or appreciation for Rush's on-air style, content and his delivery. As the audience matures, develops tastes of their own, comes to well-based, well-developed differences in philosopies of their own - these contrasts will appear and as time goes on, become more pronounced ...
The comment about "going downhill" was in regard to the Hugh Hewitt radio program. Rush's, imho, seems to have improved. He seems less apt to dwell on himself nowadays.