I have been planning on using M3s for all my ATMOS surround speakers for a while now. But with the current sale I'm rethinking some aspects of that at least for the bed speakers (ear level). I will probably stick with M3 ceiling and heights for weight and size reasons but thought I'd seek opinions on getting rid of the stands and using M50s or M60s for ear level side and rear surrounds. I heard somewhere that base response mattered in surrounds but i'm not sure where the frequency cut off should be.

On the bookshelf side I toy'ed with M5s for these for aesthetic and money reasons but felt the floor models made more sense.

So M3/M5 vs. M50/M60 for bed surrounds.

P.S. fronts are LFRs.