I have a bit more confidence in customs, but that is apple to oranges comparison. Either way, they are an obstacle that has to be overcome, and to that end I strongly encourage any frequent traveler to get TSA Pre. And if you are an international traveler, consider Global Entry for getting into the US, or NEXUS for Canada. I actually discovered that NEXUS is superior to Global Entry in that it includes Global Entry and is half the cost at $50. (Note that if you are coming into a US customs location from Canada, you use Global Entry entry via your passport.) The downside is that it is a bit more difficult to get since you have to go to a Canadian entry point that offers it. I got mine when traveling to Vancouver. But it is well worth the effort if you travel frequently between the US and Canada. My first time into Canada I waited in a customs line for almost 45 minutes. Subsequent visits were about 5 minutes. And coming back into the US it is a wonderful experience walking past hundreds of travelers waiting in line and walking straight up to the customs agent. The time saved easily pays for the cost. Also, because both systems are automated, you don't have to go through the interview process, you simply present a receipt to the agent and get maybe a question or two and then on you go.
Mexico also has a similar customs access, called SENTRI, but that is for car travel rather than airline travel, and requires using a specific vehicle every time. I don't travel to Mexico for business, so I didn't get this service.
Back to the discussion about the TSA. Here are some tips: do your research regarding TSA requirements before you go to the airport, even if you have TSA Pre, and have all your ducks in a row. If you have TSA Pre, know what you don't have to do and have to do, and be prepared to comply before you get to the agent. When you get to the agent, smile, be polite and friendly. You can imagine what a thankless job they have. A little friendliness, tends to help a smidgen and when they profile you (don't be fooled, they absolutely profile) they will be a bit more forgiving if there is a question about something in your bag - sometimes. Also, being prepared and moving quickly through the process, also tends to make the agents a little happier and less frustrated. Don't get me wrong though, they still have to comply with their "security" required checks, so you aren't going to be able to get out of a search if you do something you shouldn't, even if you do it with a smile.
I hope the above proves helpful to you on your next trip.