I have been into SUP for a couple of years, Great in FL over the winter and on the Columbia when I'm in Hood River, OR in summer. I have 2 inflatables; a Nash One 12'6 touring board and a Slingshot 11'6 all around. They're very rigid and stable when properly inflated, and store easily when deflated.
SUP gives you a great full body work out, especially the core, when you do it properly. You owe it to yourself to get a quick lesson on proper technique and rent one and give it a serious try.