The housing and body of the M2 feels much more solid than the M1
The M2 feels much more sturdy as a whole, when compared to the M1. This is partly due to the aluminium build. The cabling is also different as the M2 offers silver plated OFC wires that are twisted and sleeved together. It feels much better overall in terms of build when you compare it to the M1.
Again, I wore the M2 for the whole day the next day and after hours of listening to my playlist of classic rock and alternative indie, I can assure you that it is as comfortable as its little brother. Which means, if you are really fussy and particular with comfort, you won’t go wrong with either the M1 or the M2.
However, when it comes to the sound quality of the M2, to sum it all up in one sentence that’s within the grasp of the layman: it sounds like the M1 upsized. It feels even more musical and warm than the M1; and in every aspect, you just get a bit more. Highs, mids, bass, sound stage, dynamics – all just better. The bass is more snappy and punchy and has more presence, the mid is sweet and it pushes out the vocals, the highs is slightly higher than the flatline and it is smooth and comfortable.
In some ways, it makes you feel that this is what the M1 should have been.
If the M1 is able to fight in the same league as the Westone UM1, the M2 definitely has a better chance of beating it. However, as with IEMs, it is all about personal preference. Some might prefer a more ‘realistic’ and honest reproduction of the sound. I like how the M2 sounds.