I just took the LFCS exam today and I fear I have miserably failed. Before I do a couple of comments on the exam itself, I want to point out that I am not here to whine, just to clearly state the difficulty of the exam and the level gap between the exam and the LFS201 course.
On the one hand, I consider myself an advanced user: I admin several machines (some of my own, others not), which I have all installed and where I set up different services (ssh, http, vpn, (s)ftp, samba, etc.). I like to write my own bash scripts. I am not a sysadmin pro, since it is not my job, but one could say I am a sysadmin amateur (an advanced one).
On the other hand, I am a university professor, so I try to be objective when it comes to evaluations.
The exam is done through a virtual terminal which is open on the browser. Because of this, all shortcuts/hotkeys are "broken" (e.g. ^W will close your browser and terminate the exam, ^N will open a new window, ^P will open the print dialog). For people like me that barely use the mouse, it is a nightmare and a great loss of time. Copy-paste can be achieved through the mouse mid-click, but it is also tricky. Since many file/folder names are of the kind "CMCOS10001541", it is hard not to commit typos.
The exam consists of 30 questions, each one of them with 3 to 5 literals (so to say). Sometimes the literals must me achieved sequentially, sometimes not. Some of the literals may require several actions, some simply one. Some questions/literals are not easily understandable. You have less than 150 minutes to complete the exam, i.e. 5 minutes per question. Taking into account that reading and understanding each question will take you at least 2 minutes, you are left with 3 minutes per question to answer them. If you use man pages, which you can, you will lose lots of time.
In terms of content, the exam goes deep into the LFS201 course contents and far beyond. Different subjects intertwine at each question, for instance you might be asked to turn on a virtual machine, make sure that it starts at boot and that it uses a file which is linked to another file and that their SELinux/AppArmor context are consistent. You might be asked to use a PAM module, which you will have to determine, in order to achieve a specific goal. You must know the basics of bash scripting and the use of common shell tools like grep, sed, find and, obviously, all the basics ls, cp, mv, rm, etc., but at a really advanced level (know most of the options of each). You must know how to install and configure to some extent well known services ssh, http, etc. Also, the order of the questions guards no relation with the order of the subjects in the course, you might be asked about security, then user management and then system rescue.
There is a big gap between the LFS201 course and the LFCS exam. I can easily do any course lab (and much more) with no help, but I had to look at the man pages at each and every exam question (even for a simple cp), which was a great loss of time and it did not always gave the answer I sought (master the use of man!). Moreover, some (several) questions are not covered in the course or, at least, not in the same detail. For instance, the LFS201 course explicitly avoids iptables, which was the 2nd question on my exam. I achieved a 40% of the exam, but I think I could have completed a 90% of it with the twice/thrice the time.
In summary, my opinion/complain: I do like the exam contents, it is complete and non-trivial, which gives reputation to the certification. So I am happy with that. However, I truly believe that (1) the environment is counter-productive (they should look for a solution on the shortcuts/hotkeys), (2) the time is not sufficient and, most importantly, (3) there should be labs at the same level than the exam. I have payed for a course which is supposed to be a preparation to an exam, but it is not, it is merely an extended introduction. It pisses me off to think I have the ability to complete the exam but I couldn't because I was not well advised.
Anyhow, I will give it another try, because I am confident I can do it. If you plan to take the exam, my advises: (1) master man-pages, (2) know the most part of the options of "basic" commands, (3) learn the basic of common services, (4) go deep into all the course's chapters and (5) try to think in intertwined scenarios.
Cheers and good luck!