I haven’t hooked up my portal to this yet what’s the improvement?
Performance on the PS5 Pro itself.
Games just look better, it's just at 1080p and no HDR.
It's not going to look like 4K on an OLED, obviously. Remote Play just streams the image that's normally displayed by your tv to your Portal, so whatever benefits you get on Pro, you get on Portal (within the limits of Portal's screen).
Edit:
For example, rn I'm playing Ratchet & Clank at Fidelity Pro with RT Reflections and RT Ambient Occlusion both at High and 120hz at AUTO (got a 120hz OLED connected to my PS5) and it looks amazing and plays smoothly. Even more smoothly at Peformance Pro.
Just at 1080p with 60fps screen.
The whole art is subjective.
I would never recommend upgrading form base ps5 to the pro for the benefit of a portal. That is madness to me.
I never said I advice anyone to buy a Pro just for Portal.
It's an added bonus that happens to be a big benefit to me, as 90% of my gametime is spent on Portal due to having a family.