There are several significant problems with TrueCrypt. Somehow, they fall into different domains, so for most users only one of them really matters.<p>For FOSS-champions thing is that TrueCrypt developers are sneaky and don't accept contributions, so that in practice there is little outside control, and "given enough eyeballs are bugs are shallow" doesn't quite work.<p>For technical users, admins and frugal geeks TrueCrypt hides several unpleasant surprises, such as the encryption being undoable without a huge spare disk.<p>For casual users interface is cumbersome and counter-intuitive at times. It's almost as if developers have never considered usage scenarios. You have to type your passwords more often than strictly necessary, and sometimes you have to remember to do it, with risk of losing your data.