I'm of the opinion that the Cleveland and Boston orchestras in the early '70s were at least the equal of any in the world. I can't base this on actually hearing every orchestra live (who can?), but on the recordings I have from that period. The achievement of Szell with the Cleveland Orchestra (late '60s-70) and what I've heard of Boston in the early '70s (before Ozawa) is truly remarkable. I'm not taking away from anything done by the RCO, BPO, or VPO--all excellent--but I believe the two U.S. orchestras at that time could stand toe-to-toe with them. Some of this depends, of course, on who was on the podium at any particular time.