I only have second-hand information. So far most of the responses have been positive. The only negative is that in some airports you were not allowed to accompany your bag to TSA inspection. Try to encourage them to let you.
Two items of advice. First, check the TSA site for the latest info, print a copy and take it with you. Second, check you're airlines site as they may have more restrictive rules than TSA. For example one airline (I can't remember which one) required ammo in a separate bag.
Another hint. I recommend a COM safe http://www.center-of-mass.com/. It takes up minimum room, meets TSA requirements and the cable can be looped around internal parts of your bag to minimize casual theft.
For the most part is painless and successful.