I found studying for the JLPT straightforward. So far, I've only taken and passed the N3 level. Maybe I will be trying to tackle the N2 this year.
The J-Cat helped me confirm that I'm in fact on track and bettering my overall Japanese language skills.
I wasn't aware of the BJT; I will look into that further in the future (probably after passing the JLPT N2).
There's also the 日本漢字能力検定 or more commonly known as 漢字検定 (Kanji Kentei) which strictly evaluates one's knowledge of Kanji.
JLPT certainly is one of the easier exams (compared to other language exams) to prepare for given the fact that production ability is not tasked. Having said so it's still quite a feat to get N3! Best of luck to your N2!