Sat the test and passed this morning. It's definitely not everyone's cup of tea for sure, given it's approach is designing an optimal network rather than just getting down an dirty and building it from scratch using the CLI. Needless to say I was itching to get back to the command prompt.
I studied about three months for this using mainly Michael Shannon's CBT nuggets and the OCG. It's theory heavy and threw in a lot of material that I would have thought would be more in like with the CCNA Data Center track. Who knows, they might with the next iteration. Since I've already cleared ROUTE and SWITCH, I figure I might as well attempt the ARCH and go for the CCDP. From what I hear, that's where a lot of the fun is. If you've got the time and determination, I say go for the CCDA. If you like to play in the IOS sandbox, stick with the R&S, Security, or Voice tracks.