I have an Axis 49 (Harmonic Table layout - and years out of production) but in recent years I've taken to using a computer keyboard with Wicki-Hayden bindings. It lacks a bit in range and consistency but it's very easy to access. However I will also use traditional keys and practice my scales on them.

Each of these options develops different muscle memory and creative tendencies, but it is easier to work out modulation possibilities on the isomorphic layouts. Getting the Axis49 was like an instant "level up" to my theory skills because it made so many things come together visually.

A recent piece of hardware that lets you try the isomorphic layout cheaply is the Hyve touch synth: https://www.hyvesynth.com