As you can see from deck plans, it’s on deck 4. I have only been on Ovation, and yes, it has windows. As to crowds, most of the time it will be crowded from 5-7. It also depends on the sailing and how many diamonds and above are on board. They are also restricting usage during those hours to only Diamond + and Pinnacle, if the Diamond and above numbers are high. But only during happy hour, not the rest of the day.