I was on Humira for a little over a year and am considering going back on it. I used to take Remicade and had to stop due to allergic reactions and loss of response. The only side effects I had from Humira were injection site reactions (just a whelt) and frequent upper respiratory infections...much less side effects than what I had on Remicade. The Humira kept my gut in remission but didn't help enough with the arthritis, so I switched to Cimzia. Now that I am off the loading dose, I think it is helping much less with the arthritis, and I am out of other options, so considering going back on the Humira, even though it doesn't help as much as I'd like.
The websites and doing research online can make it sound very scary, but all of these drugs have side effects. I know of someone who was just diagnosed with lymphoma, which they believe was caused by Remicade. But, you have to choose between the risks and the benefits, and sometimes you have to try it to decide if it works well enough to be worth the risk (and cost).