I'll just point out there is at least one person on these boards that did not like the M5s. I don't know this person's reason for this.
In my living room, the M5s, like almost every other Axiom, boomed. The M2 bookshelves, M2OW and surprisingly the active LFRs did not. The M50s were pretty good too. There is a wicked bump at around 100Hz on the M3 and M5 that likely exacerbate bass effects in certain rooms.
When I placed the M3 and M5 in the main space, I had nice bass.
As for thinness in the M2, I have not found that in both the on-walls and the bookshelves.
