I've compared my new m22s to the new onwall 22's side by side, personally I like the regular m22's a lot better. The onwalls alone sound very good, but a sub is a must. To me they sound hollow or thin compared to a full bookshelf. Even with a sub, they don't have the same presence in the mid bass and lower mid frequencies that a full speaker enclosure can give you.
I'm not trying to say they sound bad, they don't, but physics can't be cheated.