There are about a million things that I love about living in Central Florida, but the water is not one of them. It isn't heavily treated because the soil it passes through before being pumped out of the ground does a pretty good job of filtering out the stuff that's really bad for you. It's not so much the hydrogen sulfide smell that bothers me (like a lot of things Orlando, it reminds me of vacation), but rather it's the hardness of it. Bathroom surfaces get filmy, and I swear my skin has reverted to having issues as if I was in college again.
As far as drinking water goes, like any other modern fridge that has a water tap, there's a filter. It does a remarkably good job of even getting out the hydrogen sulfide smell. But the problem is that I don't know that you can really install a whole-house filter or softener. People don't have basements here, so it's not like a single pipe comes in from underground and then distributes water around the house. A pipe comes in and enters your foundation, where it splits out. If you wanted to install one thing into the line, I assume you would have to do it in your front yard, between the house and the valve (which I think is somewhere in the lawn).
I guess that's the price of sun and palm trees.
I know that whole-house water softeners are occasionally installed on houses in Texas. A friend of mine lived in the Austin area and he had one that was in his garage. Of course it was designed into the house before it was built because of the water quality, so that probably addressed the issue of where to install it, but I know it is possible.