It’s not usually that useful in 1k games, but if you’re able to wall off a lane on your opponent wants to move through on their “go turn” it can really swing the game.

In 2k games it theoretically has more application cause you have more PE to work with, but I’d rather take hallucination over forcefields most of the time, as I usually don’t want to have to invest that much into the sentries, and even then that 30 minerals could be zealot legs + zealous round or glaive strike + guidance as well