We stayed a week at each place last October.
Mira Vista. We rented a 1 bedroom condo and it was spectacular. Marble and glass and leather. Couldn't be better. That said, the resort is small and attendance is small. Basically we used the place as 'home' to travel and see Tucson. Management tries but there were so few people there that if you are looking for tennis players or volleyball or whatever there just were not enough people. However, the resturaunt was very good and shopping is near and we brought in our own drinks and such and had a good time.
Shangi La. We rented a 1 bedroom condo. Basically 1/2 a park model. It was OLD, very old. But also very clean.
What it lacked in rooming it more than made up for in fun.
We played Pickleball every morning with about 12 to 16 others. We played water volleyball every afternoon. They had dances and cook outs and just lots of stuff to do.
Everything is far way. Stores and supplies would take 30 minutes each way.

So, Mira Vista is a beautiful resort. Lots of attractions around. Peaceful.
Shangri La was kind of old but hopping and friendly and just great fun.

The 2 places are just as far apart as can be.