I am currently BJCP certified and have been for a little more than four years. It has benefitted me, but not so much in a sort of stature sense.
Preparing for the test certainly made me more aware and better able to spot flaws in beer. Of course, it also taught me a little more about how to manipulate ingredients to achieve my desired results.
It also made it easier for me to judge homebrew competitions, and that has been even better. You can try commercial examples, your own brews, and your friends', and that will help out over time. However, it's hard to find another chance to sit down, sample, and really be charged to think about several beers that are all in the same or similar style that that, most likely, come from different brewers. Then, do that a couple more times during the day. Then, come back another time and do it again. The tasting experience has been invaluable, as has the chance to talk about those beers with another judge.
The test is tough, guys, but it's worth it. If you are looking for a chance to take it or prepare for it in your area, let me know. I know a bunch of folks who tend to know a bunch of folks all over. I may be able to help you find something or, at least, let someone know there is some interest in a certain area.
TL