I have had an M3 both ways (With and without EDC). Skipping EDC was a no-brainer for me on my latest M3 (ordered this one). If you run coilovers it's a button that becomes useless and you have to code it out. I was not impressed with the EDC suspension settings (I rarely went out of the middle mode). In the end coilovers are the best option considering you can tune the ride quality and height.
'13 M3 - Silverstone II - Sold
'04 M3 - Jet Black - BBS E88, KW Clubsports