each individual needs to follow what is right with them. I know several people who never wanted to test, and usually got dragged into it unknowingly (took an hours worth of ukemi; got called up to test during a regular class, etc). I know one man who never has taken a test in his aikido life, yet is a third dan who's been practicing 20 plus years.
Definately a "to each his own" problem.
My last "test" was a demonstration for my sensei. It was really the most difficult "test" I ever had to do, because I had to think about it, prepare, and had no excuse to mess up! I learned a great deal from that "test", and am glad I did it. But then again, that is me, and others could/would feel completely different.
You'll know what is right for you. Just work with that.
all the best,