IMO, the problem with Claude Code, OpenCode, Pi is the harness quality and convincing the agents to do the exact things you need, to define workflows and make the agents stick to it. I didn't experience performance issues.

For example I have an agent in Claude Code that has strict rules to do something before implementing every phase in the plan. Sometimes it decides not to do it. "But, wait the feature is simple enough so I can proceed straight to implementation..."

Just because this is written in Rust won't solve the biggest issues most users have with coding agents.