I wear a size 32D bra (band size: 29" cup: 33"). I have to have the straps fully extended to avoid ride up when the straps are in the crossback form. While the material is thinner than most bras (no padding) it can effectively hide nipples, and support smaller breasts, enough as it would in a wired unlined bra.
I wanted a bra to wear casually that could withstand getting soaked with sweat or absorbing body odor and that was versatile enough for many different styles; this seems it will do the job with it's straps and v neck.
The only real faults I can find are that I would've liked a little more padding (maybe a little more support with this), and slightly thicker straps. The straps are just elastic and can dig into the shoulders after a few hours.
The options for wool bras are few, and while not perfect, this seems to be one of the best available so I will be keeping it. Hopefully future versions will improve upon the straps.
NOTE: don't go by the size chart for chest measurements. According to that I would wear a XS. I got a small previously for the non vneck style and my breasts were popping out the sides. Especially for this style, you don't want a boob bump under tight shirts so I would either be prepared to try/return multiple sizes as I did, or read reviews for fit examples!