Getting back to tweeters, I don't have a lot of experience with a lot of different current-generation domes and ribbon(-ish) drivers, but I've tried a fair number of different compression drivers and many different diaphragm types. My preferences tend to be for polymer diaphragms (rather than metal diaphragms) up until you get to the price point where true beryllium diaphragms enter the game. Since my design choices place a higher priority on the horn or waveguide than on the compression driver, and a higher priority on synergy than on excellence in isolation, matching up the exit angle of the compression driver with the entry angle at the throat of the horn or waveguide is a consideration, which does limit my compression driver choices somewhat.
Duke