We did both restaurants and this is what we found...
Sole Mare is not as good as Gianni's. Service was not great and the food was not as good (may be they are sending their better chef's to Gianni's??) and the atmosphere....no comparison.
We ate outside but under the canopy, so the wind was not an issue. We found inside noisy as of the high ceilings. Depends on the number in your party. If you are a large group, then inside would be fine as "you are the noise"!!
We really ennjoyed the food. Service on our first visit in December was amazing. Service on our second visit in Feb. was not as good.