About couple of weeks ago I succesfully passed the LPI 202-450 exam and got the LPIC-2 certification.
I would like to thank Terry and the Linux Academy community for the support and the courses provided. Also special mention to Emil Vulkov who gave me good tips to pass the LPI 202-450.
Few advices for those who will attempt the LPI 202-450:
Obviously try to complete the whole course on Linux Academy. Follow the videos, not only watching them, but also practicing so you can pause a video until you understand and get the things work.
Play as much as you can with the options and directives in the main config files.
In my opinion this is the most difficult exam so far, so you need to read/study from other resources apart from LA, personally the "Exam prep by Snow B.V" and
"LPIC-2: Linux Professional Institute Certification Study by Christine Bresnaham" helped me a lot. I find them quite complementary.
Go to LPI website/wiki and look for the changes they made from exam LPI 202-400 to 202-450, I think they tried to emphasize the changes on the test, there will be questions about IPv6 and Sieve (not easy to find good resources about this).
Finally as other people mentioned here, study the main directives in the config files (dovecot, bind, samba,sshd, ldap, dhcpd, postfix..) and be aware of other "less important" directives even if they are not covered in detail.
Thanks to all Linux Academy community!