Ahh so hard to choose. I'm very tempted to order both and have a nice A/B session until one comes out the victor.

And my question between the two is really about which pair of speakers is better at bringing the electric guitar to life. I know it would all be personal taste, but sometimes the electric guitar can get sterile sounding with a completely flat response. The frequency response chart of the M3's have some interesting peaks in the upper midrange/treble that look like they may be fun along with the added bass.