I came from an M1 Air too and the MBA 15 is noticeably brighter, in accordance to specs. What surprised me though is I turned off True Tone on both the MBA 15 and MBP 14 in-store and set brightness in both to max and couldn't see a difference (see photos from a few posts earlier). The MBP is supposed to be capable of HDR and 1000 nits but I just couldn't see the difference with brightness manually set to max.
I even tried playing 4K HDR content from YouTube and there's a difference with better specular highlights on the MBP 14 but it wasn't a significant difference to me. Definitely not mind blowingly impressive to my eyes. I was actually more impressed by the image from the MBA 15's larger display when side-by-side to the MBP 14.
I loved my M1 MBA 13. It still handled my photo and video editing needs admirably. I didn't need to upgrade per se, but just wanted more screen real estate. Usually I had the M1 MBA connected to a 43" 4K TV most of the time. I am torn between the more powerful MBP 14 and the adequate-powered-but-larger-screen MBA 15.
I thought I'd prefer the higher resolution of the MBP 14 but in-person it seems so diminutive next to the MBA 15's display. Both units had Final Cut Pro installed and, despite the lower resolution, it seemed more appealing to edit on the MBA 15's larger display. The included media files were only 1080 and the MBA 15 scrubbed through the timeline with ease with smooth playback. I didn't have any 4K clips to test with in-store, unfortunately, but recall my M1 Air handled those just fine for basic video editing of family vacation videos. I suspect the M2 in the MBA 15 will perform slightly better than an M1 MBA.