My company paid for me to get precheck/globalentry years ago and I still have it after having left. I can say from my experience about 99% of the time it actually is a shorter line and a much smoother experience. And even in cases where its not shorter, it can still be faster since people don't have to take off shoes, belt, etc.

To add to this, the line is also faster because you're not dealing with the people who never fly and can't figure out how to put a bag on a conveyer belt.

It's not always shorter, but it definitely is the vast majority of the time.

As someone who pays for TSA precheck out of my own pocket, I can tell you my expert opinion: I absolutely pay for shorter line.

Global Entry is for immigration, TSA is for security checkpoints.

Global Entry includes TSAPre

jen20 referred to a global entry line, and kova12 referred to tsa lines, which are unrelated lines in an airport.