Apart from that, x86 is IMO just easier to adopt. I wouldn't buy an ARM laptop right now (except for possibly a Macbook).
In a different tangent, I think the only way to get good ARM performance in a mobile format is to have custom-tailored silicon, like the Apple chips. Commercially available chips just don't compete with a i7-1265U or the Raptor Lake equiv.
In my eyes (uneducated, consumer-level perspective) X86 is a huge question-mark for HMD devices like this, since the heat and power usage are so counter-intuitive for small form factors -- and mitigating those concerns usually actively works against the "higher-performance" nature of the chips. (low-tdp allowances, throttling, etc.)
Like I mentioned above, I really do wish y'all the best of luck with it. I just don't envy having to be reliant on an old and power-hungry architecture just because the newer, better architectures don't lend themselves to this sort of project yet. I hope the Simula One sticks the balance!
I'm sure one could do a more rigorous comparison, but IMO with the recent Intel/AMD chips you get pretty good performance/power.
If I had to buy a backpack laptop from them (And I would kinda love to have a backpack laptop + weird goggles, be kinda like the "Gargoyles" from Snow Crash) to get their display, happy to do so.
I think it's a less elegant solution overall, but it's an option (eg for supine computing or to lessen the head weight).
I'm actually really excited for Lenovo's upcoming T1 wearable display. It's a monitor in glasses form, not VR, but I realized that the appeal of VR desktop environments for me is having a large screen, not the whole VR shtick.
Couple that display with output from my phone running JupyterLab, and I'll have a desktop-like development environment that fits in my pocket. Perfect for travel and long backpacking trips.
Their dedication to developing a true VR computer and focusing on specs that really matter for that (PPD and raw processing grunt) are commendable, but seeing them champion the idea of strapping an X86 computer to your face in what is an increasingly arm-powered world is... concerning. "But it can run real Adobe Acrobat through WINE" is not something that gets me excited about a VR platform, but I'm likely not the target audience either.
That being said, having tried out some remote-desktop apps on a Quest 2 earlier this year, the screens are absolutely not acceptable for that purpose in terms of viewable resolution -- so if the Quest Pro really is only slightly better in that regard, I think it'll soil the experience.
If Simula can manage to tune their x86 specs to run well enough under power-limited circumstances, have at least comparable poor battery life to other VR headsets, develop a VR computing environment with usage paradigms that make sense, and do it in a headset that's somehow still comfortable to wear for extended sessions, then they may truly be ahead of the curve in a way that matters. That seems like a big ask for such a small company's first outing, but they also seem the most passionate about this category of use-case despite their scale.
I wish them the best. VR computers like the one they're working on would be a lot cooler than Meta's vision for the category.