We sailed in an infinity balcony for the first time on Celebrity Edge in early April. We absolutely hated our so-called "balcony".
One night, we kept the window open, as we love to hear the ocean while we're falling asleep. And, the window is so sound proof that there is no ocean sound when it's closed.
During the night, when it became increasingly warm in the cabin, I tried to close the window. However, the window was stuck and would not close. So, we sweltered for the rest of the night. We contacted our cabin steward as soon as he began his shift in the morning and he immediately contacted a technician who arrived promptly to fix the window. According to our steward, this is quite a common occurrence due to ocean salt getting into the window tracks and causing them to jam.
After this cruise, I am determined never to book this category of cabin again. You may as well save your money and book an ocean view.🙁