i use it at work, not because it was my first choice but it was already in place when i started working. i picked it up and the best thing about ColdFusion is the learning curve. its so easy to do. security is good with ColdFusion cuz everything is prepackaged so you dont have to be concerned too much about the security of the scripts.
the downside is that because its prepackaged scripts basically you are somewhat limited in what you can do. you have to be able to write your own custom tags. the speed of ColdFusion is also an issue. these forums just lag when i use my Apple laptop. in general ColdFusion is a little slower over all on any platform from my experience. its also quite expensive. Macromedia is supposely making some changes to ColdFusion now that should be pretty big. i believe ive heard that there will be a CF to ASP convertor of sorts. i heard that in one of my meetings from another guy so i dont know how valid that is though.