Are they at "feature parity", is there some things that Claude Code supports that Open Code does not have, and lastly is there a noticeable difference in quality of the output of the two?
OpenCode - you can easily see the changed files on your branch, it defaults to being permissive with tools, can easily fork a session so you can fix unrelated issues or small issues without consuming context, you can add more “modes” like build and plan as a first class construct, you aren’t limited to just Anthropic models.
Claude Code - you can do all of the above in one way or another, not least if you use an IDE with it
I started using OpenCode to get away from the horrible Claude flicker, but it seems that they have fixed that recently - I don’t think I’ll be going back though, and I use Opus/Sonnet exclusively.