There is indeed a lot of power in the E-A7 for drum editing. I used the Dynamix drums and liked them but I just bought one kit as I didn't think the different kits were varied enough to justify the price. Also, you can probably make the default Roland kits sound just as good if you take the time.
Hi Tracy was waiting for your reply as you already experienced at least one of the Dynamix drum kits there's so many more,....I am experimenting as you and Fran have stated also on the editing power the Roland EA7 makeup tools offer to let you get in to EACH separate part of the kit and rework it till you get the desired results as I did with my G1000, G70, BK5, etc, also. After all that's is what an arranger KB is all about creating YOUR sound with it.