My experience with three sets of M5 bookshelves and one on-wall is that 30 hours of break-in is needed for the woofer and mid-woofer to blend properly. One of those pairs of bookshelves was broken in when I got it. I maintain someone at Axiom threw a party with them. I'm happy about that because I like my gear burned in before I get it.

I've said before, I have no idea what exactly is breaking in. You may hear a vast improvement before the 30-hour timeframe.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated