Here are some pics in some sunlight. I used sunlight coming through a window as full sunlight would be difficult to photograph. I compared this to my Macbook Pro both with Brightness 100%
This photo taken directly into s glare reflection
Then from the best viewing angle
I think both about the same and equally hard to read but if it is your thing to work in the sun with your computer, then its possible. If it is just to read, get a Kindle.
I will say however, that with these 2 displays next to each other, the Macbook tops it by far, the detail is not lost just because brightness is turned up, but that's probably to be expected..