They are certainly growing in popularity and I have heard nothing but positive responses from people who own them. I too have MANY stories of people trying to sell their home with a swimming pool in the back with little success. Some here are even filling them in to sell the house! At least with a swim spa, it's portable and you can take it with...
Less expensive than a pool, takes up less room, less maintenance, the ability to have a quality exercise and a longer swim season are just a few of the benefits.
Here's a link to one I've personally used and found it incredible!
http://www.swimspas.com/Steve