There is a substantial amount of spam and NSFW posts on the All page coming through already. Most NSFW posts aren't being tagged as such and are coming right through. I am not sure how this can be weathered but we need something in place fairly soon, I feel like we are days away from rivers of bad stuff, especially via some of the federated instances.
EDIT: I personally don't care much about the NSFW aspect, more in the lines of what a newcomer will be seeing when they get to the main page. 99% of the newcomers don't know / care about federation and have no idea how to turn that off. Liability for the server owner is also an element of consideration.
Just an individual opinion but I see way less spam than I see on Reddit when I sort top past hour. I haven't seen any advertisements yet for t-shirts or mugs. I've seen a couple of meme channels that I have blocked. I've seen very little racist postings. I see some diverse political commentary. I have seen very little or no troll posting within comment chains.
I find the amount of people coming here and criticizing the activity pub protocols and the apps that are using them seem to have an agenda. We're living in an ecosystem that is basically getting its first real test. Tools will be built to address these things as time goes on.
Another thing people don't talk about is the amount of moderation that's needed on Reddit to keep it semi-usable. A lot of those moderators have now left and have been replaced with lower tier mods. A lot of the auto mod tools are going to stop working in a couple of weeks. This is only the beginning. I already see a large change in what shows up in Hot or r/all. A lot of us didn't like the way Reddit has become anyway. All it is now is a vehicle to push ads and it's no longer about community and discussion.