The MP6 is an improvement, but in-ceiling speakers for any of the fronts is a bad idea. You end up sitting virtually 90-degrees off-axis from the speakers’ output. If you have access to some regular bookshelf or tower speakers, turn them facing the wall to get an idea of what ceiling-mounted fronts will sound like. You get drastically reduced definition and imaging.
Naturally I understand that the appeal of in-ceilings is aesthetics. If that’s more important to you than audio performance, that’s certainly your preference and no one can fault you for that. But at least now you know what you’re getting.