I have tried both headsets, the Omnicept is just like the G2, slightly better construction IMO (materials) which also means a little heavier. AFAICT image quality is the same. AFAICT the tracking is the same. The Omnicept has additional sensors (eye tracking, face tracking) but they all require special support, which is typically only implemented for certain Enterprise applications. It’s definitely geared towards professional applications, ie companies that have specific software requiring the extra sensors.
The eye tracking for example, is not usable for interactions in MSFS. It is however usable for Foveated Rendering with the OpenXR Toolkit.
I personally don’t think the extra sensors on the Omnicept justify the higher price tag, considered that very few applications actually take advantage of them (and I’m not sure it will really change in the future).