Actually I would add that bore size for lead players is frequently even smaller-.492 is often used and .500 is even more common (the King 3B is actually .508). There is a trend to play larger bore horns (Steve Turre, Robin Eubanks, Slide Hampton). The bore of these horns is in the .547 range, which is a considered a "large-bore" tenor trombone and is usually favored by orchestral players. There are still many jazz players who play the smaller .500 range horns, however (my personal preference ).
There are advantages to playing the smaller bore- it is for the most part more facile (making it easier to get around and play faster and more angular lines) since its optimum range is in the area of the overtone series where the partials are closer to one another.
The larger bore tends to have a bigger (i.e. darker, rounder) sound and can access the lower register more readily. These are generalizations and there are always exceptions- I wouldn't say that a smaller bore horn automatically affords the player a higher range (this is after hearing Slide tear it up on a BIG axe!). I do think if you "hear" a dark sound, you will get a dark sound regardless of equipment.
I performed at a trombone convention in 1982 or so and one of the guests was Jimmy Cleveland (Wayne Andre was another). I volunteered to take Jimmy to dinner and had a great conversation- at that time he hadn't been playing a lot and was not quite up to his usual spectacular level, but he sounded great and it was a thrill to meet him. I don't remember what horn he was playing at that time.
Jimmy's playing really knocked me out from the first time I heard him. I'm glad to see some renewed interest. I want to read your dissertation when it's all done, VE!
I would be interested to hear what *slide_advantage* might add to this discussion.