Yes, my first certified step (pun intended

) to the dark side. I followed the Fast Track materials for about 2 weeks, with a little delving into the JunOS Cookbook and some of the JunOS Security Handbook (not much though as I'm on a pretty tight deadline to get the basics down before we do some proof-of-concept with SRX's). As others have said if you have good experience and/or similar certs from other vendors the fast-track materials are more than enough for this. I think the hardest thing for me to get used to was the examples always being displayed as show results in the std. XML format, it's not hard to mentally translate that back to perhaps more familiar SET (Cisco-like/direct config) style but it's an extra few brain cycles each time. After week or so it became easier to do.
For practice I had some access to a SRX3400 that is assigned for another POC project, I couldn't do much with it but was at least able to play with the various show commands and doing some routing with BOGON addresses...If I broke anything in the process well at least nobody noticed

Sooo, on to the JNCIS-Sec (I should have 2 SRX100s on the way for the home lab so it'll be a little easier to practice).