The slider works fine on my Atom HE. It’s only the Classic range as far as I am aware that requires buttons.
On my Statement, Roon sounded better running on the Statement as core than on the Nucleus+ - which itself sounded better to my ears than either the Naim Core or various NAS devices such as the QNAP fanless models with SSDs (even beter witheh SJ PSU).
However Sense on the Statement sounded even better. So I only use Sense now. Alhough the Nucleus is still installed, connected and kept up to date with every release, I never use it, except for certain guests.
Surely, the +/- volume buttons are available, on any Naim item that requires volume adjustment.
I did think that Sense sounded quite good, but in my system and room not as good as Roon Nucleus running Core and powered by Volt power supply. The Zenith just running in Roon bridge mode.
Streaming radio was very little if anything different from Sense. However Quboz and ripped cd library showed a noticeable difference, even in blind conditions.
Sense (at least currently) only provides a slider, irrespective of which streamer (ND555 or Atom HE) I select.
Thank you for your input. The +/- volume control is currently at testing stage now, as can be seen in Innuos feedback.