A lot of people when they first come to Japan they just want to learn the language so that they can get by in a day to day environment but if you are interested in working in the corporate world in Japan and stepping out of the education sector, the JLPT is going to be a test that you have to consider. For most jobs in Japan a minimum for working in an office would be the JLPT level 2 test. This is in no way an easy test if Japanese isn't your first language. They are many parts of grammar that probably weren't covered is your basic Japanese texts and if you don't buy books specifically for preparing for the test, there isn't much that you can do to get ready.
Although this is a difficult test I would have to agree and say if you aren't at this level you probably shouldn't be working inside of a Japanese office. I have done it before I wound up being free all of the time because they wasn't enough work for me to do at the level I was at. Now that I am progressing in my Japanese more I feel like there is more that I can do to help out if I were to go back into working at a Japanese office.
There is no other test that will let Japanese people know how good you are at Japanese. There is a test specifically designed to see how much Kanji you can read but I really don't think Japanese people care about that. The JLPT is the only test that you can take to let people know that you have skills in the language. It kind of sucks but at the same time it is a really good thing. If they were many other tests then Japanese people would have no way to simply figure out what level their employees are at.
On the other hand there are several tests that Japan holds for Japanese people who study English. The most popular would be the Eiken. I actually had a high school student pass the highest level last year and he could hardly speak a word. The JLPT and the Eiken don't measure whether or not a person can speak in that language and that is one of the problems with the tests. This actually resulted in many universities in the UK from not using Japanese standardized testing as a measure as to whether or not a student is ready to study in an all English university.
Is it worth it though? Make no mistake, if you want to pass the JLPT 2 or JLPT 1, the amount of study time you are going to have to put in is going to be huge. I would say you really need to ask yourself, "what sector of work do I want to be in while living in Japan?" If you want to stay in the teaching sector then I would say it really isn't worth it. If you feel like you can get by and have conversations in Japanese then don't worry about it. On the other hand I feel that having a bench mark to measure yourself and see how much you have truly improved is a great thing. When I recently signed up to take the JLPT 2 I felt a drive to study again that I hadn't felt in quite a while. I am glad I have the opportunity to test myself because after college there aren't a lot of opportunities to do things like that. I have only a few months left until the test and so I will be studying as much as possible and be writing two more blogs on the subject. One after the test and the other after I get my results back. Thanks for reading.