I generally quite agree with @Pharmaboy’s descriptions of Aeolus and VO, but I do feel the Atrium is a “warmer” sound than he describes perhaps?
I absolutely love its midrange presentation, it has perhaps some of the sweetest though balanced mids I’ve heard. How it voices acoustical instruments and things like classical violin, cello, or piano are just beautiful. It also does slam pretty hard in the bass when you’re rocking out! 
I am using U perf lambskin pads on mine.
Regarding Aeolus, it also depends on your chain, what else you have in headphones, and what you’re looking for it to do for you…
I’ve tried it with the Univ perf lamb (stock pads), Aeolus pads (very very warm, punchy bass, but to me too much of everything), and Univ perf suede.
I found the stock pads “just right”. To me, the Univ suede pads pushed it to a more “technical” sound more towards a Verite, or a Focal Clear OG. This was using a Burson Soloist GT. Aeolus will “scale” with better amplification too. Prior to getting the Burson I was using a Schiit Lyr 3, which is a fine amp. But the Burson really took them to the next level with clarity and resolution, detail retrieval, and imaging.
But I found I preferred the more balanced but fun sound of the stock pads. I have other headphones for high level resolving of detail and razor sharp clarity.
They also love tubes! (like all ZMF dynamics do)