from everything I have read and auditioned n my research of both solutions, On walls provided less qualtiy then the inwalls...
I have seen & heard some nice looking on wall products, like Paradigm, or B&W's being basically the same, but neither wow'd me at all... seemed to have some shortcomings in my book... Going from large speakers, I really didn't feel they had the punch or presence that I heard from in-walls... They just sounded like large computer speakers if you know what I mean...
I still haven't gotten the time to go out and audition more In-walls... but I will