Sandvox is a well-designed application, but I consider it utterly obsolete and irrelevant at this point.
If I just want to get something up and running fast and easy with minimum fuss, online services such as Squarespace.com, Weebly.com, WordPress.com are far more suitable for such scenario and they still offer CMS and social capability right out of the box, which Sandvox doesn't. And then, if I want more than that, open source CMS platform such as self-hosted WordPress and Concrete5 would give me the power to do all kinds of custom work while also keeping me from reinventing the wheel via plug-ins and premium themes, none of which Sandvox can match.
WYSWYG is one of Sandvox's selling points, but the thing is that web is not WYSWYG. Gone are the days of web design driven by print design mindset. Web is about usefulness, mobile access and social media. The whole thing has become more like a web app development, and Sandvox doesn't address these needs much at all.
Overall, I believe that the era of Mac web site generator such as iWeb, Sandvox and Rapidweaver has come and gone, and these apps will go the way of the dinosaurs in a few years. It’s no reflection on the quality of work fine folks at Karelia Software. But for someone who follows the current trend in web site design practice at all levels, Sandvox just doesn’t make sense any more.