can this be better than samsung s25u? Tempted for not switching from s24u

Tempted but it doesn't allow me to use CC, and no two tone.

mi 9T is using snapdragon 730 series , for sure the experience wont be good , i been started using xiaomi is the 10T without the PRO which is snapdragon 865 with 144hz refresh rate , superduper good ! And always remember hunt for 8 series chip no matter what ,  because it's the high end line for the snapdragon
For the 15ultra , u wont dissapointed with the latest 8Elite chip....it blow away in term of speed & efficiency

about the buggy software that people keep complaining , i not sure why i really didnt face serious issues on my xiaomi 10T , after 2 year i pass to my dad to continue use lagi....recently just changed new battery and stil stand strong......he also never complain any bug issues , he just keep saying that "That phone is fast compared to his old cheap phone , charge very fast too" 
For the samsung phone what i dont like is the shutter lag , did u feel shutter lag each time u snap the photo on your samsung phone?

For me don't expect much from Xiao mi. The issue many don't understand its call optimisation. I had a poco phone they have tons of ads, everything is ads, browser got ads, system apps got ads, everywhere ads, hope their ultra don't use similar concept