I personally think that instructing is an invaluable step in the progression of any career, not just the airlines. Do I like primary students? Yes and no, I think that it can be extremely tedious to take 5 or 6 primary students in one day 5 days per week and just go out and do slow flight steep turns and stalls over and over again until they progress to the landing phase and then you just do pattern work 8 hours (logged) per day. That being said you get a tremendous feel of satisfaction knowing that everything they learn and every concept they grasp is because of you and you should feel good about that.

On that same note everything they know is because of you so it is imperative that you do anything and everything within your power to make them a better pilot then you are. Do not ever be afraid to admit your faults, I have done it many times and everytime they have been appreciative for the correction, I will call a student after I go home for the day just to tell them I was wrong so my incorrect information will not sit in their head longer than it has to.

The skils you will develop flight instructing are evident almost immediately, like others have said, every single phase of every flight you are analyzing technique and all of the four phases of flight and what they are doing in relation to your airplane at every given moment. What is happening now, what will happen if the student does this etc etc, you will be thinking two hours ahead of the airplane at all times and really feel the plane and its capabilities.

Advanced students are an easy way out if you simply skip the primary, although still rewarding you are doing a disservice by not sharing with the fledgling pilot community your knowledge to the primary students. On the same note you are still doing your part to better yourself and help someone achieve their goal and you will develop solid instrument skills by teaching others instrument, you will really start to learn the system.

As for multi students, I personally believe that no one has any place teaching in a twin until they have proven they can teach in a single. It took me 500 dual given before I was allowed to teach in the twin. Just because you have your MEI does not mean you can teach in a twin. If all is going well then you will do just fine, but what about when things go wrong..your 20 hours of PIC wont help you. There are many schools though who are hurting for instructors, to include MEI's so there is a great chance you can just walk in the door and step into the twin. Also being said there are twice as many student pilots looking for instructors as instrument candidates and so on up the list so you will be needed for everything, not just the "good stuff"

On a final note...if you kind of want to instruct but not really...honestly, just go to ATP to instruct or Ari Ben. Both of those schools hire brand new instructors, put them in the left seat of the twin immediately and then expect that you will leave as soon as you hit 400-500 hours. It is a win win situation for both of you.

Hope some of it helps in some way.

USMC