I don't think there's a night and day difference, but maybe a partly cloudy to mostly cloudy comparison
The M149 IS more authoritative under 100hz, but 3db boost in that area on the K2 I thought was indiscernable. The only other area I thought begged my attention is the strictly siblant area, which a quick dip @ 1k and up brought closer (I used ElectriQ just screwing around here).
In the end us K2 owners sometimes get flamed, but NEVER burned
p.s. However the K2 can't be compared to a polished C12 or T3 sound (I think).