When I first tried DMS, I was skeptical. It's new. It's very fresh and you can feel it. There were some broken links in the homepage. There are still some bugs. Googling stuff that usually brings lots of solutions instantly with other themes etc. might not bring you anything (as the community and support forums are so new alse).
Also, all the drag & drop -themes I've tried in the past have been horrible and I really did not think it would be possible to create anything usable with that philosophy.
But DMS is different. It's amazing, I love it and it has actaully changed my entire design process. It has also cut the time of developing sites by about 40%-90%, depending on how much customization I need.
With the time I need for coding custom stuff being smaller, I can now focus more on great overall design and serving my clients needs better.
The first huge problem DMS solves, is that traditionally with WordPess you can only create pages or posts. And if you want to have i.e. boxes of content on a landing page, you need to create a page template and hardcode the content. Or make the boxes from posts and loop them or something. There just hasn't been a good solution.
But with DMS you can just drag and drop boxes of with all kinds of contents to your site and customize the text/content in the front end. This is the biggest, awesomest thing DMS brings to the table and it just takes some much time out of the process.
Second thing that I'd like to stress is that DMS is for developers. It's NOT the "drag & drop -system your grandmother will learn to use" and that's the best thing about it. It's so developer friendly, and doesn't frustrate me by being "too easy" like most solution like this do for people who actually know their way around HTML, CSS etc.
Third thing is the responsive grid, based on Twitter's Bootstrap. It's just se well made, so fast, and it just works.
Up until this point I've custom coded pretty much everything to make it as good as I want and work the way I want it to work. But DMS is so good that I made the decicion to always use it. So there is just one framework to use, and all the code used in previous projects is easily available as custom sections I've coded my self.
I first bought DMS for one page for one month for $8. In a week I ended up upgrading to pro and doing all of my client work with it, even using it with more complex custom layouts ordered from me by graphic designers.