To actually answer your question, I prefer the buttons on my SS1 to the buttons on one of my dive buddies' Octo-Z. Both breathe adequately well for their purpose and both have the convenient threaded attachment to the corregated hose. I would spend the extra $40 for the SS1.
FWIW, I've read all of the arguments on here against integrated inflators, and have used mine to assist an OOA diver, and will continue to use it (as do my tech-trained dive buddies.)
Thank you for answering the OP's question. We don't get much of that around here.
I’m not familiar with either of those Inflator/Regulators, but consider the servicing aspect. If you service your equipment yourself, Zeagle allows parts to be sold to the owner, Atomics does not. However, if you don’t service your regulators yourself, then you would have to take it into a dealer-you already own an Atomics regulator, so logistically the SS1 would make a better choice.