I'm just back from Scottsdale where I stayed at the Kierland. My own thoughts:
The Kierland is a very nice property. If you're into golf / spa you'll have a great stay here. The rooms in the main hotel are quite comfortable. I had a room on the 11th floor overlooking the golf course. I would say the Club rooms (9th floor) are probably a bit nicer only because some of the rooms on the 11th overlook the rather noisy exhaust fans on the roof. I think I was in room 1149 (towards the middle of the hotel) and it was just fine. My only nitpick is that the balconies are quite small.
The breakfast at the Kierland is expensive. I think it was $22 + taxes. The selection is pretty good though. They also have a Starbucks / cafe by the reception area where bagels + muffins are available at much more reasonable prices. For the truly price conscious there's a Safeway up the road.
Sadly I was unable to try the Deseo restaurant for dinner which I've heard is pretty good.
I also passed one night in a Casita suite. It was about 80 - 85 sq.m in size. It was a one bedroom unit (King of course) with a Queen pullout in the living room. A fully-stocked kitchenette rounded out the primary offerings of the suite. The dining table was quite large and could comfortably sit 6. Nice / interesting touches included 2 flat screen TVs, a DVD player, a Bose Wave radio, a large balcony and a stacked washer / dryer in a closet by the entrance. Wired internet in the suite was free. I couldn't get the free wireless to work, but I have my own travel router so I just plugged it into the wired and that solved that.
The Casita was a pretty quiet room as it's located a distance away from the main hotel. If you stay in a Casita but want to partake in the main hotel restaurants and other amenities, you're in for some walking (or calling Service Express to send the golf cart over). Personally I don't think this is a big deal but that's just me. Casitas incidentally have their own separate pool, gym, convenience store etc.
Wherever you stay at the Kierland (room vs suite) you have to pay the resort fee. Personally I think this is silly. If they really must charge an extra $20 per night, then just inflate the room fee by $20 and call it a day. But I guess the airlines charge a "fuel surcharge" so hotels feel they can charge "resort fee". Anyway, the resort fee gets you "free" wireless in the hotel as well as a hat and a large tote bag.
Across the street from the Kierland (which is pretty far from the hotel) is a semi-interesting collection of shops in what's called the Kierland Commons. As a hotel guest you get some small discounts such as buy one get one free @ the Starbucks, free appetizer at some of the restaurants etc. I've heard the seafood place is decent but I didn't get a chance to try it myself.
I made it a point to visit the Phoenician. In one word - spectacular. It's clearly a different class of hotel. I would have been interested to see a room though. My impression from the outside is that the hotel is older. If the rooms have been renovated I would expect a very comfortable and happy stay. If they haven't been renovated I would be grumpy paying those rates! Nonetheless, the grounds are something else and I suspect the dining is a notch or two above the Kierland.
There are suites (villas) available at the Phoenician similar to the Kierland. Unlike the Kierland the Phoenician villas are not merely expensive. I saw the villas from the outside and they appeared to be quite new so I would expect them to be modern on the inside.
There are 2 other SPG properties that may be worth a thought. The Sheraton Oasis Villas is an isolated property at the end of a dusty road. If you want to get away from it, this is the place to go. Once you get past the apartment block adjoining the Sheraton, there's nothing except desert! Some people will find this appealing. While I like the desert (a lot!) I would not personally want to stay at a place that's as remote as this.
There's also a very new W that more or less adjoins the Scottsdale Fashion Mall. This is probably the best place to stay if you want to shop 'til you drop. It's not my thing but again, some people will find this appealing.
One final point on the Kierland - if you're Gold or Plat you will probably be offered a meeting to hear the pitch on Starwood Vacation Ownership. SVO is essentially timeshare, but you can trade your week in for either SVO points or standard SPG points. I took the meeting and found the concept interesting enough to give it serious consideration. (For various reasons I didn't take the plunge in the end.) At time of writing, the Kierland is the only property that can offer SVO for any other property. For example, if you stay at the Westin in Maui they can only offer you SVO at the Westin in Maui. The Kierland can sell Maui or Cancun or ... There is no obligation to take the meeting so feel free to politely decline but do be aware they will most likely offer a meeting to you.