Short recommendation
Use GitHub Copilot (Copilot Enterprise) as your default VS Code inline assistant for daily coding and test scaffolding; add ChatGPT (Enterprise) seats for engineers who need long multi‑turn design conversations, multi‑file refactors, or deep explanation workflows.

Why: at-a-glance
- Inline completions: Copilot is built for editor “ghost text” and offers the fastest, most IDE-native experience inside VS Code. It uses workspace context to produce on-the-fly completions and code snippets.
- Test generation: Copilot quickly scaffolds unit tests and test cases inline; ChatGPT often produces more thorough explanatory tests when you prompt it explicitly, but requires extra prompt/response steps.
- Privacy & compliance: Copilot Enterprise includes org controls, SSO, and policy features designed for code-first teams. ChatGPT Enterprise offers strong data protections and longer context/memory controls but is typically pricier per seat.
- Multiturn context in VS Code: ChatGPT (via its extension) is stronger for sustained conversational sessions across multiple prompts. Copilot focuses on ephemeral context (current file/workspace) and is better for continuous inline completion than extended multi‑turn dialogues.

Decision criteria (pick what matters most)
- If you prioritize seamless inline completions and lowest friction in edit/test cycle: choose Copilot.
- If you need multi‑turn design discussions, cross-file code generation, or richer natural language Q&A: add ChatGPT seats for leads/architects.
- If strict data residency, audit logging, and per‑seat policy controls are required: evaluate both Enterprise offerings against your security checklist and legal team.
- If budget is limited: Copilot per‑developer seats are generally more cost‑efficient for broad developer coverage; ChatGPT Enterprise is higher per seat but can replace fewer specialized licenses.

Practical evaluation checklist (run this in a 2–4 week pilot)
1. Pick 3 representative repos (different languages, monorepo vs service). 2. Measure developer workflow: average suggestion acceptance rate, time saved per task, and latency. 3. Test test-generation: ask both tools to write unit tests for 3 realistic functions; compare coverage and fragility. 4. Verify privacy controls: SSO, data retention, telemetry opt‑outs, and legal terms with security team. 5. Try multi‑file refactor: ask tools to add/change an API across files and measure correctness. 6. Evaluate admin tooling: user provisioning, license management, and audit logs. 7. Track cost vs usage: monthly seat utilization and ROI.

Best‑for / Avoid‑if
- Best for Copilot: large dev teams that want fast inline completions, high throughput, and affordable per‑dev licensing.
- Avoid Copilot if: you need heavy multi‑turn architectural conversations or enterprise policies that your security team rejects.
- Best for ChatGPT: architects, security reviewers, or small teams that need deep conversational sessions and cross‑file reasoning.
- Avoid ChatGPT if: you need cheap per‑dev broad coverage for daily completions.

Final note
For most enterprise dev teams: standardize Copilot for everyday coding and tests, and keep a smaller ChatGPT Enterprise allocation for higher‑level design, code reviews, and multi‑turn workflows. Run the 2–4 week pilot above and use acceptance rate + privacy compliance as your deciding factors.

Compare GitHub Copilot and Cursor