I was 1k for years before becoming GS. There is a very significant difference between the two with the most important being how you are handled during irregular operations. For us, that’s job security. As a GS, I’ve had my reservations reworked before I was even aware there was a problem. Weather, maintenance, ATC problems, doesn’t matter. If they identify you might not make a connection, they start working a solution. Either a different flight, or they meet you at the gate and drive you across the ramp, or through the terminal to your next flight. Since it also comes with lounge access, you also gain the benefit of a United agent in the lounge who can help work issues. Can’t count how many times I’ve walked past lines of a thousand people in IAH or ORD waiting for customer service, and I’ve walked into the lounge to an agent with no line. 1k comes with none of that. Really the 1k benefits for the kind of travel we do are essentially useless. We’re flying in business class for most international flights anyway. That means you’re boarding in group 1 no matter what your status. The 1k “hotline” can take 45 minutes to get someone on the phone. You get your first choice of meal, but the food isn’t that good anyway, so it doesn’t really matter. And when the sh*t hits the fan in a commute or deviation, you’re mostly on your own to find a solution.
To each his own, but once you experienced the difference, it’s pretty easy to see the difference.