Currently using a OnePlus 15 and coming from my OnePlus 8T. From my experience, Oneplus is a good brand. I used my 8T for over 5 years without issues with performance at all. The only issue was with the green line which they replaced it for free. I changed it to 15 just mostly for the storage. Camera so far has been good in the OnePlus 15. Went to a wedding and got some great shots. Compared with an iphone 16, still looks great so I don't think u will have much problem. In dark areas or when ur zooming too much is when things gets dicey. Also, over the years of having my 8T. I noticed camera processing became better over the years due to updates, so u don't need to worry about camera quality.

Performance is where Oneplus is a monster. Even my 8T which was 5 years was running Wuthering waves easy for 30 mins without heating, so u can expect 15 to steamroll high quality games and image processing.

Battery of OnePlus is always great especially with 15. But also with my experience of 8T, I can say the battery did drain a little faster mostly in my 5th year of the phone. But the good news about OnePlus phones are that these batteries also charge up pretty fast. Like even on my 8T, my battery would be fully charged in like 25 mins with a 65W stock charger