Look for the highest nit rating you can afford but check if that's the maximum it runs at all the time, i made the mistake recently of buying a phone with a very high nit number unfortunately like many here have found phones will automatically reduce the brightness to save the screen so basically they dim as they get hotter.
(see thread below)
What budget do you have?
Really loved flying the
Air2S with my Galaxy 22 Ultra and 1633 max nit brightness. The Galaxy 23 bumped up to 1750 (no reason to upgrade for me), but the Galaxy 24 coming out at the end of the month is listed at 2600 nits. Remains to be seen how long it would last at max brightness in the sun without overheating, but definitely interested to check this out. By comparison I see online the Iphone 15 Pro Max is 2000 nits max.
Again will be interesting to see how long they will hold that brightness in the summer without overheating. Looking at the Tripltek tablet which many have touted...