In my quest to find to the perfect Warm + Sweet IEM, these are the four contenders. I am an audiophile newbie so any help on deciding the victor is appreciated. I listen to all genres of music but probably Hip/Hop Rap the least and Hard Rock + Folk/Singer Songwriter the most. I will also be mainly using these with an iPhone/iPad.
I just got the M3 and had the M2. Overall they're slightly more refined, and I like the design more, as the strain relief on the drivers came off the M2s and could be annoying. Bass impact and depth is very good. I was expecting these to be more polite than the M2s but so far (I just got them so they're not broken in yet) they're actually quite punchy in the low end, and very smooth in the mids and treble.
I think you should really consider the Woodees Vintage Stereo Earphones. I loved my A151 until I got these. They have an unbelievably natural sound with a warm presentation and surprisingly good soundstage for an IEM.