It has better color consistency and tonal range in the shadows, and as tested it covers 100% of Adobe RGB rather than P3, which is still a respectable 94%. I like the UHD Plus screen more than the OLED, though, especially for photo editing, which is arguably the creative work that this system is optimized for.
The problem is that standard OLED panels only come in standard 4K UHD 16:9 aspect, so the XPS switched to a nonstandard 4K 'UHD Plus' (3,840x2,160 pixels) and a base 'FHD Plus' (1,980x1,200 pixels). The XPS 13's display has a 16:10 aspect ratio, which means both the XPS 15 and 17 follow suit. For one thing, that means the XPS 15 ditched its 4K OLED option. Dell redesigned the XPS 15 (and introduced a new 17-inch model) for 2020 to align more with the XPS 13, mostly.
