I have a cotton knit unconstructed blazer and quality is really goog.
Fit on blazers/jackets is slim in body and sleeves, very similar fit to Our legacy blazers for example.
I wear Medium sizes in too many brands and Barena size 48 fits me perfect, like tailored.
Sleeves tend to go long, probably you will need to visit your local tailor
If you buy a cotton knit blazer, don´t put it on a hanger because the fabric will deform on the union of the arm and shoulder.