I have been a trip leader for 5 years now.
I find that it is very rewarding. I started the job with the intent of getting paid to ride my bike, but I work with kids, and now find that helping them grow through the experience of a loaded tour expedition far outweighs anything else.
The pay is nothing, but I don't place value on money, so it doesnt really matter. The time in the field has payed off now that I am a bit older, I am qualified for higher-end tour positions and other related outdoor work. Just as with any job, there is room to move up.
I would highly reccomend it provided that you dont care what your bank account reads and that you are not responsible for other lives (kids, dogs, wives, etc.) If you are a single person who has perfected living on less than 10k, then you will have a wonderful life in this field