I don't see how you can do giant sets in a commercial gym. How can you tie up the leg press, leg extension, leg curl, while you're at the squat rack? Giant sets are great for a well equipped home gym. I have very little experience doing giant sets. I can't imagine anyone could handle heavy weights doing them.
I once tried to do a giant set of leg extensions, leg press, squats and leg curls. I planned to do a couple of series but after the first one I was done. I guess pacing and the correct weight used is a big consideration. I went near failure on each exercise.
I remember around 1976 the most ripped guy in the country was Joe Means. He used giant sets but he trained in a private gym. Makes me want to consider them again.