Grok has started competing with frontier models on coding thanks to Cursor's data, with SpaceX's massive compute they can undercut competition on price, which makes the offering real appealing.
I've now switched to Grok 4.6, I was previously using Opus 4.8 but Grok is good enough now, and way cheaper which is the important part.
The $20 / month isn't as good as Codex or Claude. Codex reset twice this week while I'm sitting waiting for the entire month to role around with Cursor. I have all three so can have a pulse on everything.