A little late to post but I passed the CCNA:S. Though I barely passed I found the test much more theoretical than actual implementation. In the past, I took a class that was focussed on the CISSP and I believe that that was the biggest help with this certification. Like others have said in CCNA:S posts the Boson materials are invaluable and using a combination of Chris Bryants Udemy videos, and the 31-day book is essential. The OCG was only worth it because I got the book for free. The OCG goes very in depth in some areas that aren't needed and breezes over essential items. I had a few weeks left of a CBTNuggets subscription when I started studying for this cert and the material was very good. If you can get your hands on the parka document I highly recommend it.
Overall it took me about three months to study for this exam. I've worked with ASAs a fair amount in the past and wished to get a better understanding of them and hopefully move into a more security-based role at my new job eventually. From here I'll get the SSCP, then CCNP:RS, and finally CISSP.
For those currently pursuing the certification don't be discouraged by the perceived difficulty of the exam. Yes, the topics are vast but take it one day at a time and lab whenever possible. Also, don't be discouraged by failing and having to retake. Failing is one of the best things that can happen to you. It keeps you humble and encourages you to identify your week areas. As always the wording for certain questions were horrible and if I was talking to a person requesting certain tasks and could ask them to clarify more about what they are looking for I believe I could have scored much higher.
I only had one lab and two drag and drop questions. Know where everything is in ASDM and how to expand certain child elements from submenus. You will not be able to fully browse the ASA but rather then let this frustrate you use it as a clue for where you should look if unaware.
*Edit: If anybody has any particular questions about the exam I'd be more than happy to answer them. While a little dated the following Memrise link is also a great studying tool. memrise.com/course/787865/ccna-security-3/