There are two ways to look at this. In-walls look good, and if you use a good quality speaker, sounds good also. An added bonus is in-wall's also keeps the wife happy too. The other side of the coin is speaker box design is a science, and the sound quality will alway sound better than a in-wall speaker. At least if you use a good quality speaker. I won't get into naming brands of speakers, as I have found it's a personal choice of the installer and, or the clients ears. My personal opinion is a speaker in a box designed around the spekers installed in them will always sound better. If you prepare the wall you are installing an in-wall into you can come close, and have a good sounding room. Also, do the math on your room size etc.

Hope this helps
Datahead