Everyone who goes to the airport dreads the TSA lines. For me, it isn't so much the "actual" time that it takes to clear the line as much as the variability that it adds to your total commute from your house or workplace to the airport gate. In Chicago, commuting is already a (bad) crapshoot, with traffic that can grind to a halt in inclement weather and an ever expanding rush hour. Thus you need to significantly pad your travel time estimates to prepare for a trip to the airport that could go 1 hour plus from downtown.
On top of that, you have the TSA lines. While I've been through the line in a few minutes, I've also spent 45 minutes in line. This is another random roll of the dice that you need to plan for atop traffic while trying to get to your destination.
For a while the airlines have been favoring heavy travelers or business / first class travelers with expedited travel lanes. I never quite understood the logic of this from a fairness perspective but I certainly understood it from the airlines' perspective - this allows them to give a significant perk to their most loyal travelers.
Recently I noticed that the TSA pre-check lines have become ubiquitous at major airports including Chicago, San Francisco, Atlanta and New York (just the ones I've traveled through recently). While I snake through a long line, I enviously watched other travelers waltz through security without emptying their bags, taking off their shoes, taking out their laptops and liquids, and the rest of those tedious and semi-humiliating tasks.
I joined that coveted class when I paid $85 and filled out an online form and met a government contractor (I assume it was a contractor) for an interview that took about 15 minutes including wait time. You are able to schedule this interview through the web and submit your paperwork in advance so that it goes very smoothly (it might have gone longer if I didn't pre-submit my information, I don't know). They give you a "known traveler number" or KTN that you need to put into your frequent flyer profile on the major airlines and then when you book a trip and print a boarding pass (or do it through your phone), you can see a "pre check" green check mark on your boarding pass which allows you to expedite your trip through the TSA screening process. There are FAQ's to this process and they recommend that your name on your travel profile needs to exactly match what is on the KTN documentation - so that if you fly without your middle name and it doesn't allow you to pre-check, then you may want to ensure that you book with your full name going forward.
The $85 buys you 5 years of pre-check screenings. I expect that, over time, many more individuals will join the pre-check ranks and soon the lines will be just as heavy with travelers as the "traditional" lines are today. However, these lines are definitely faster because you are just throwing your belongings onto the conveyer belt for the scanner and ensuring that you don't have anything metal in your pockets which means you go quickly through on the front end and even faster on the back end. I am just guessing but I'd say that these changes would make the TSA 5-10 times faster in terms of total capacity.
I'd highly recommend getting the TSA pre-check even if you are only flying 2-3 times / year - over 5 years that would pay off in multiple hours of savings getting through the check out lines and less stress in the airport.