I've been one of those people waiting in the TSA security line to see CLEAR passengers "crowd" in at the front of the line. It can be a little irritating. However, there are all sorts of places where "line jumping" is part of the process when it comes to flying. Usually how one feels about it is whether you are the jumper or the one put behind the jumper(s).
SEATAC airport has "save a spot" program which is similar except it is for regular security line and it is free. Make a free online reservation and get whisked to the head of the regular security line. Great if you are the one getting ahead. A little frustrating if you are the one that has just waited 60 minutes in line to get to that point.
I do think that applying for Global Entry, especially if you are about to head out of the country makes the best sense because then you can interview upon return and not have to worry about snagging an appointment at an interview center.
For those of us that access the Canadian Border frequently, the Nexus card is really the best deal out there. It comes with Global entry and TSA precheck thrown in, but it is using the fast lane at the border that makes this card worth its weight in gold.