I am pretty sure I have seen a few shill posters on here, but I wouldn't say the forum is under a spam attack, as I rarely come across a post I would genuinely consider completely spam. I think a lot of people come here thinking that they have finally found the promised land, and then realize this is more hostile territory than they are used to, and their low quality posts won't be tolerated.
I have also observed this. I saw a post by a member here posting that he is having problem getting his first merit. I was responding to his thread after few days and he already got 3 merits till then for other posts. I checked his past posts and they were much better than the posts he made before making hat thread.
I also remember a post about someone selling his house for bitcoin investment. It looked like a way to get attention and was quite old post. When I checked recent posts of that person, he was making awesome contribution in alt coin section.