The Comprehensive Economic Trade Agreement (CETA) between Canada and the European Union is the first treaty to specify new rules governing the identity and tenure of arbitral members and provide a more extensive review function through a two-tiered investment tribunal system (ITS). CETA signals a shift towards a more public and judicialized system, akin to that of many national legal systems and the World Trade Organization. The ITS creates a permanent first instance tribunal and an appeal tribunal (featuring a pre-elected roster of tribunal members), which is competent to review the tribunal’s decisions for errors of law and fact, as well as on the grounds of Article 52 of the Convention on the Settlement of Investment Disputes between States and Nationals of Other States (ICSID Convention) — making it a novel one-stop-appellate-shop. This treaty comment assesses the operation of, and reasons for, key provisions of CETA’s Investment Chapter and examines the extent to which it addresses points of criticism and lessons learned from the experience of arbitrating under the North American Free Trade Agreement and other open-textured treaties. The analysis draws analogies to, and distinctions from, other treaties and relevant jurisprudence that have influenced the negotiators. Among CETA’s most striking features are its purported modification of existing arbitral rules (ICSID Convention, ICSID Additional Facility Rules, and UNCITRAL Arbitration Rules) and its removal of disputing party involvement in the selection of the tribunal in favour of a roster appointed ex ante by the state parties, which results in a considerable amount of the investor’s autonomy being stripped away. While these and other issues must be further analyzed and balanced in the context of present discussions regarding the creation of a multilateral investment tribunal, CETA nevertheless contains significant procedural and substantive innovations and stands as a guide for future treaty negotiations and reforms of investor–state dispute settlement.