I was GS for several years and it really made flying just so easy. The most valuable benefit by far was how well they sorted things during IRROPS. I liked the dedicated checkin, that put me at the front of the line for Security. I recall one occasion where they were already asking for a volunteer to take a later flight, my plans had just changed, and they put me on that overbooked flight - the two people who were bumped were delighted as they were given travel vouchers, so everyone won! Another time, when I missed the last flight back to the UK, they made sure I was on the very next flight. It was nice knowing that if I missed a flight, I would always be on the next one, and usually up at the front - that seems to happen a lot when you fly domestically, especially during the winter. Also international operational upgrades seemed far more frequent (than BA gold).

I only became GGL in March 2020 and haven't flown since then. But as gold, upgrades were few and far between, other than W to J on LHR-NYC.

So not really and apples to apples comparison. But if I had a significant amount of domestic US flights, i would go with United.