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.
Without giving too many details I thought it would be fun to make 2D games based off of banned books (sort of as a marketing ploy, paradoxically everybody likes banned books). Camp of the saints seemed like a good target, which is a fictional book based in 1980's France dealing with incoming flotillas of immigration. I found that ChatGPT would push back on the premise of the novel instead of coding, while grok models just called things "edgy" and went to work.
I have more examples (mostly dealing with realtime web filtering) but that's the immediate one that comes to mind.
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.