Besides getting a cert, was it worth it? I would say in case of this particular exam – yes. I was already familiar with many topics covered by the exam but it did fill some gaps in my C# knowledge. And I enjoyed learning the new bits. It also did feel like I had to learn some details by hard at some points, which was less enjoyable.
What did I use to prepare myself? I used the official practice exams from measureup, the 70-483 ref book, the Wrox Certification Toolkit book for this exam, in a few cases the official documentation and of course – StackOverflow. I feel the practice exam was very beneficial, the official ref book was also helpful but in my opinion very badly written. It’s as if the book has no structure and as if the authors didn’t communicate between themselves so that would make sense and so you could learn in some kind of logical order. Instead, the book jumps between topics in an unexpected way. The Wrox book was ok. I didn’t go through it in full detail, but read a few bits and pieces where I felt I wanted to get more details which I haven’t been satisfied with by the ref book. Both books seem to be riddled with various mistakes in code.
Overall, I’m very happy I studied for this exam and that I passed. If you’re considering doing it – do it, you’ll be happy to learn new things and it isn’t really that hard but be prepared to put some time in it. Good luck! :)