I've got both. I started with unmodded MK3's.
The Mayflower mods definitely improve the midrange presence, and tame a bit of the treble which can seem harsh at times.
BUT, the M1060s are in another league entirely. EVERYTHING sounds better on the M1060s. Granted, I did have to mod them slightly to get rid of the upper midrange honking, but the M1060s wins hands-down. Plus they're way more efficient.
If I could do it over again, I would have just sold my unmodded MK3's and put the money towards the M1060s.
Looks like we took somewhat of the same path, except your saving me some of the pain lol This is exactly what I was looking for, great feedback! I love the MK3's, and if the 1060's are better even with the mayflower mod, this seems like a no-brainer. Thanks Spinny