Yes they are useful! Stop badmouthing the MBTI descriptions. Okay, sorry I know that sounded childish. Well, the thing is I wanted her to ignore the order of functions completely, but focus on the personal decription that works very well on deciphering who you are, doesn't matter whether you adhere to socionics or MBTI, it is still very good.
Also go to
http://www.personalitypage.com/high-level.html to read some descriptions. I think the socionics descriptions are fine, but their not personal enough and confuse people.