Before you upgrade the M30s suggested you do your room acoustics if you havent done so. They make up 50% of your sound. Once you get the acoustics right, then you'll wonder what made you the itch to upgrade. M30 has potential provided they have adequate and proper room treatments in rooms they are played in.
If however your room is already very good , I'd probably consider the SHL5 as the next speaker up. The speakers you listed above are all very good but harbeth has that midrange magic.
If however your room is already very good , I'd probably consider the SHL5 as the next speaker up. The speakers you listed above are all very good but harbeth has that midrange magic.