While the Kempinski Ishtar might be a newer/ nicer property, I believe the Evason Ma'In is a superior place to stay for the following reasons-

-It's a vastly more interesting setting with the spectacular canyon and waterfalls and hot springs, yet still close to the Dead Sea.

-I thought the dead sea was only worth spending an few hours visiting as swimming there is bizarre and the 'beaches' are nothing special. Also, you can get day passes to the Dead Sea resorts for approx $25-50 depending on which one you choose and have full access to the resort amenities.

-Close to Madaba.

-Sunset dinner and drinks at the Panorama restaurant.

Hope this helps. We stayed at Ma'In and did a day trip that encompassed Madaba, Mount Nebo, and then a few hours at the Ishtar in the afternoon. Ended the day in the hot spring at the Ma'In spa and then had a few Petra beers while watching the sunset at the Panorama. Perfect.