There is no reason to be disapointed by M60, I think. Although I do have the M80 and very happey with them, so far all speakers I heard from Axiom are very good and quite pleasing. The rest is just a matter of room size and budget.
The number of great posts on M50/M60 and all the bookshelves has made me confident in recommending any of those lines to my friends according to their needs and budgets.
There is a very simple mechanical tool you can use to sort out bad recordings from good ones. One is made of plastic (sometimes with a metal frame), the other (if you are ecologically inclined) is entirely biological. You either need: 1) A garbage bin or 2) A nephew or niece to hand over part of your collection