It can be very useful to set the log level of Tridion’s content service to Debug every once in a while. I admit I always do that on my own development environments – you never know when you will need it. Of course, I would not recommend it for production environments but that’s another story.
One thing is really annoying though: every 10 seconds, the content service makes a call to the discovery service (for whatever reason, perhaps to check the validadity of the tokens or something). And this leads to so much logging that you always have to wade through endless lines of useless logging before you get to the interesting bits.