I just got to know about this new M30.2 which appears to be a 40th Anniversary Edition from the Harbeth newsletter. What is the difference between the M30.1 and 30.2? From the description the M30.2 doesn't seem to be very different from the 30.1.
http://www.harbeth.co.uk/special-editions/monitor-30-2.php
http://www.harbeth.co.uk/special-editions/monitor-30-2.php