I use pipewire myself, so it is less a matter of consistency than it is overall quality. Suppose the closest approximation would be going from a low tin can quality with the latest mainline kernel to crisp and clear after installing the Neptune kernel. 

Dunno what Valve has done, but they've included some additional patches to their kernel that make the sound far more superior by comparison. Could be proprietary drivers for all we know. ¯\_(ツ)_/¯