The best time to go to the practical exam is in the 3rd week after a 3-week boot camp.
The first week after the camp should be used for hands-on during the free VPN week
(remember, only 3 week attendees have one week of free VPN access).
The second week for additional studies and research on matters of weakness and
uncertaincies.  In the 3rd week go to the exam.
This practice has proven successfull for many students.

CCIE 18561 Belgium

CCIE 18632 USA