The honest answer: they solve different problems
Most searches for "Cursor alternative" are really asking one of two questions: is there something cheaper? or is there something that keeps my code on track? If it's the second, the answer isn't a different coding agent — it's a layer above the agent.
Cursor is excellent at writing code from a prompt. It doesn't stop you from prompting vaguely, and it doesn't stop the code from drifting from what you meant. That's not a Cursor problem — it's a spec problem.
Executable is where Cursor's context comes from
Cursor is strongest when the repo tells it what to do. Rules files and docs help, but they describe conventions, not behaviour — nothing in the repo says what "correct" means for the feature you're about to build. Executable puts that in the repo as version-controlled .feature files: capability taxonomy, jobs-to-be-done context, and Given/When/Then scenarios sitting alongside the code they govern.
Because the specs are files rather than chat history, they show up in diffs and reviews. A pull request that changes behaviour changes the scenario too, and a reviewer can point at the missing case instead of arguing over a paragraph. The tests Cursor generates come from the same scenarios, so "passing" means "matches intent" rather than "matches whatever the agent inferred".
When you actually do want a different coding agent
Different agents have different strengths. Executable is agent-agnostic — the spec is portable, so you can switch coding agents without rewriting anything. That's the point: the durable layer isn't the tool that writes the code. It's the spec.