First I wanted to buy the e604, but the technician where I bought them, told me that the e 904 are worth the extra money because they have the benefits of a condenser but are dynamic mics (less or no feedback). They are good for dynamic playing because of the fast "response speed" (can't explain, sorry for my bad english). But a few weeks ago, I heard Stephan Maass ( well known Meinl endorser here in Austria) playing and he had some Audix (I don't know which exactly) - incredible sound, don't know how much they cost, maybe I would go for them, If I had the choice!! Tom!