I live in the area but have not stayed at either property, so my take may be different than most, but Kierland is in a busy area. It's right next to a large upscale shopping/entertainment district that is always busy.

By comparison, Wild Horse Pass is literally in the middle of the desert. It's within 10 miles of shopping/entertainment, but it's far enough out that you don't have to deal with the locals.

Based on what you are looking for, i would probably say Wild Horse Pass would be more to your liking, but they are both very similar.

Have you considered the Phoenician? That's more centrally located than the others, but it definately caters to a more upscale crowd.

you can't lose really - all 3 are beautiful and the weather is finally starting to break - enjoy your time in the desert Southwest!