Hi Outofillinois
You asked people to post anything positive about Casa Grande... Here goes

Please don't be too concerned about the recent reports of 'gang-warfare' here. I have lived in CG for 3 years and were it not for recent postings in this website, I would not have even realised a 'gang clean-up' was necessary. The fact that the district has been proactive in eradicating crime early on is a good thing and should not deter you from moving here - quite the opposite

Also - I would disagree about the supposed 'slums', 'horrible weather', 'indigent people' (?!) and bad medical care. It is easy to be negative about anywhere if you want to be. Casa Grande is not Scottsdale,

but it has many good qualities that should be considered by people looking to relocate.
Casa Grande is a relatively quiet town compared to Phoenix and Tucson, and well-connected in comparison to Queen Creek and Maricopa. It is growing quite rapidly and there are new shopping complexes and strips going up all the time. Have you seen this:
http://www.promenadeatcasagrande.com/ ? The city is changing and a new demographic is emerging with higher average incomes and different needs from a few years ago. This is driving demand for better retail outlets, schools and medical centers, which in turn attracts more residents who continue to alter the demographic. See http://biz.yahoo.com/prnews/071116/laf044.html?.v=101 (broken link).
There is certainly less 'to do' if you like a vibrant night-life, but for those looking for a slower pace it still offers quite a lot. My perspective (which I mention since someone urged people from 'nice middle class cities or better' to avoid CG!) is one of a Brit who has moved here from a 'nice, middle class (or better!)' part of south-east England, near Windsor and 30 minutes outside London. CG already has some good places to eat such as Chilis and BeDillons, there are 2 Starbucks, a Greek coffee shop / restaurant, a new wine bar called Corks which is by all accounts pretty hip, Olive Garden opening soon, as well as Cost Plus World Market, Dillards, Bed, Bath & Beyond etc etc... These major retailers don't open up a store without doing a lot of work on projections for the demographic of a place. (Does Dillards target people from the slums? Hmmm...)Historic Downtown is being redeveloped and already has nice antique stores, art shops, a theatre...in a year or two it will be a very pretty place to browse around for a few hours.
Even though you do say your children are fully grown, I would add that several new schools have opened / are being built - in fact some of the local schools now get quite high ratings, such as Mary C O'Brien (a little on the outskirts), Desert Willow and Casa Verde:
http://www.greatschools.net/city/Casa_Grande/AZ. Of course, not all the schools are brilliant so research is a good idea. And as with ANY city, bear in mind some areas of town and outskirts are 'less savory' than others (it's not hard to tell which!

). There are homes to suit all budgets, from $100k condos to $500k+ communities, $1m plus gated developments, 55+ golf communities, and so on. Not really the characteristics of a 'slum town' in which residents fear for their lives every time they set foot out the door...
Don't be scared of coming to Casa Grande, it's an exciting time to be here, the community is very friendly and you can really enjoy a good lifestyle here.
EB