They're more expensive.

There were some applications where I spec'ed them, because they made sense, and purchasing would call me and ask if they could substitute cheaper Phillips et al.

They are GREAT for manufacturing, less great when they're rusty and cruddy.

To make your life miserable. I've dealt with TORX on many european cars. They always manage to either break off the teeth on the socket or round out the bolt. I make habit of replacing them with the apropriate hex bolt whenever possible. 3-square bolts are the only ones that work properly.

It sounds like this is one of those areas where my age has been detected.

In the beginning, like in the seventies, the word was that Torx fasteners were available dirt cheap to manufacturers so that they could sell the tools. Now that some 30 years or more has passed by, now that they are more widely used, they can get more for them.

Don't get me wrong there are certain SMALL size applications where I like them, but for the most part, I would be just fine if they had never been invented.

Pretty much how I feel about them too.