The M126 has more detailed treble but is not fatiguing
but how’s the clarity? I thought I heard the M126 is suppose to be a little darker?
I have the M126be's.
I must agree with OP that they are very detailed and present in the treble. They have some of the most vibrant and satisfying highs I have ever heard while simultaneously zero and I mean zero harshness.
I was very skeptical of the added costs for beryllium and was very prepared to return if need be. Turns out they were keepers.
Like OP I run dual subs and high pass the M126be's around 80hrs. Alone they do not have enough bass for me. They are physically smaller compared with many 6.5" driver designs.
I did not have the m106's but did have the m16's, JBL L82's, KEF R3, JBL 4309, BMR, Lintons and several others here simultaneously.
Notably, for me the m126be was a clear, across the board upgrade from the m16(which is a very enjoyable speaker for me). It really was not as close as I anticipated. Also notable was how much I prefer the m126be to the R3.
The L82, Linton and BMR handle 2.0 much better.
I ended up keeping the m126be, BMR curved cabs and the 4309.
I still have the Lintons here and a couple other speakers though I plan to sell them. They are decent speakers that can swing 2.0 very well but are outclassed by most of the others above bass, IMHO and I have two subs so 2.0 is less of a factor vs 2.2