Very good, I thought it would make me feel warmer because it is long-sleeved but it is just fine :)

Tested while fishing from a boat without a canopy, and the difference it makes compared to a regular shirt is incredible. It obviously protects from solar radiation, but it also keeps the body very cool under the sun, as long as there is even a slight breeze. It doesn't smell, but because it directly absorbs sweat, it needs to be washed after each use. I have washed it by hand or in the washing machine with cold-warm water over 20 times and it hasn't been significantly damaged. For everyday shirts, I wear L or even M with a loose fit (178 cm, 76 kg), and I bought the XL which is quite comfortable (maybe the L would be slightly better). I believe that if you wear it for dry activities, one size larger is okay, but I think for water sports or swimming it should be more fitted. The sleeves are fitted regardless of the size.

Absolute sun protection... I tried the medium size (my size) and it was completely tight, so I got the L size but it stretched out a lot and now it's too big for me!