abu Dhabi is a great place for a 24 (nearly) hour layover. There's lots to see and do. I would totally do it. The mosque is beautiful and a must see. Walking along the corniche is beautiful and nice. The beaches - particularly Saadiyat Beach - is beautiful too. I'd recommend it. Let me know if you need hotel/ food recommendations - there is a lot of good to see. Not every day you get to see something different. And at the end of the day, a lounge is a lounge.