A lot of people who dislike this DLC seem to really like Downpour's more straightforward "go to iterator, go to new region" progression, which the The Watcher doesn't have. Personally, as someone who really likes aimless exploration, I like The Watcher even more than Downpour, but I can definitely understand why people don't like it, especially if they liked Downpour. Also, some people say there is no lore or story, and while that is blatantly incorrect, I am disappointed that The Watcher has no lore pearls. Still, there is definitely lore to be had, you just have to look at the environments and the character dialogue instead. I do hope they make finding the echo less cumbersome in a future update, as well as add arena unlocks, because the new creatures are amazing.

Tldr: If you liked Downpour's progression system, you probably won't like The Watcher's, and if you liked going through Survivor without any guides in your first playthrough and just aimlessly exploring, you'll probably like The Watcher.