You got a great set-up. The in-walls should be a bit more sensitive (check on the respective product pages) and they won't suffer from speaker-wall boundary interference like the on-walls or conventional boxes.

Having said that, I pointed out to you when you first started asking, that in-walls likely won't equal the soundstage and imaging you can get from conventional boxes. But, if you don't have the space, and you need everything to look clean, what you've done is the best option.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated