I've used/use it. For a while it had one of the best lightweight coding LLM's, which actually lead to a #1 spot on openrouter usage ranking although they've fallen off the top 10 used now. It's also provided some good reasoning models, which perform better when dealing with non-PC topics.

Also, although I've never used it for this, I believe some of the paid models produce some of the best "adult" content, and I know there are even subreddits which do nothing but praise Grok and "content" produces who use it.