I jumped from a 512Gb S23 Ultra to a 1Tb S25 Ultra
@Masser, and the big thing that I noticed immediately was the quite dramatic display on the S25U. Photos taken on device are displayed in super HDR, and look STUNNING. Same goes for videos (unless recording in SDR). To be honest EVERYTHING looks stunningly immersive on this device. In terms of photography, both devices take great photos, but in video, the S25 Ultra is noticeably ahead, with the ability to switch lenses while recording at 4K 60 for instance the big upgrade for me personally, and the ability to record in SDR and HDR10 and HDR10+. Stabilization is better on the S25U also.
I find battery life on my S25U is noticeably better, but both devices run cool, and feel fast and slick in daily operation. The 25U is much more comfortable in hand thanks to those rounded off corners.
I store mountains of videos and photos on device (@256Gb annually), and I found that 512Gb storage was giving me storage anxiety at the end of every two year contract, so I went for 1Tb storage this year. I hope whatever device you choose, you really end up enjoying
@Masser.