I've been on Humira since March, and it has made a significant difference in my health. I was sick for over a year, with no relief from entecort and imuran.
There are lots of threads on Humira on this forum, and lots of people are on it, just search on Humira.
There are side affects from taking this drug- some people have them, some don't. I get fatigued for a few days after an injection, get an injection site reaction, red and rashy, and some minor nueropathy (tingling) in my fingers. As for long term side affects, you'll have to way that out in your own mind. It worries everyone, but being sick for so long is no way to live. I had to make the choice for quality of life right now. Make sure to talk out all your concern's with your gi. Good health and good luck!