All of my awful caddie experiences are at courses that use an outside company to hire, train, and run the caddie program. The two worst were TPC Sawgrass and Erin Hills. They seem to run off a script, and the caddies I've had don't seem to know what they are doing (one got us lost on the course and made us walk an extra 500 yards between two holes). I have also found that courses that use caddie companies charge much larger fees. There seems to be a fee for the loop (which I imagine goes to the company) and then a large suggested gratuity. After one terrible experience, I was told that if I didn't give the caddie the entire suggested gratuity, I would have to meet with management to explain myself.
My good caddie experiences have come from clubs that seem to do it themselves, and I have found clubs involved with Evans Scholars have been great. Some of the best I've had were at Milwaukee CC, Blue Mound CC, and Flossmoor.
I also had good experiences at St. Andrews, Carnoustie, and Royal Cinque Ports.
My most memorable caddie experience was at Pinehurst. It was the first time I had a caddie, and he was amazing. He'd been at the course for nearly 40 years, and had tons of great stories in addition to knowing every bump on the course.