AJ's not bad as far as big cities go, but I hate big cities. The whole Phoenix area, AJ included, is getting more and more like LA. Too much traffic and too much smog. There are lots of places in AZ where the winters are nice and everything else is way nicer than around Phoenix.
Mobile homes are not a great investment. We had one on our own property and really had trouble selling it. It was a nice home in a great area and we had lots of potential buyers, but banks won't loan money on them any more. When you get ready to sell you will have to find a buyer with cash.
The Phoenix housing market is recovering faster than any place in the nation. If you are only renting a space in a mobile home park you may find the rent going up quickly with property values and taxes increasing. And rent is something you can't control. DH and I were renting a very nice apt in Prescott AZ and decided to buy when interest rates went so low that the payment on a bigger house was the same as our rent. And our payment is fixed.
Don't limit your looking to AJ only. There are lots of areas in AZ just as nice or nicer.