Sage X3 is the top of Sage's ERP range and it is a genuinely different class of product from the rest of this list. It is aimed at manufacturers and distributors with real operational complexity, and it is priced, implemented and staffed accordingly.
What it does well
Process manufacturing is where it separates itself. Formulas and recipes, potency and yield, batch and lot traceability, quality control at every stage, and the ability to answer a recall question in minutes rather than days. Food, beverage, pharmaceutical and chemical companies buy X3 for exactly this, and it is one of the few products under the enterprise tier that handles it properly.
Multi site, multi legislation and multi currency are native rather than modules. A US manufacturer with plants in Mexico and a distribution arm in Canada runs one instance, one chart of accounts and one set of books.
Tax and filing
US sales tax through Avalara, Canadian GST and HST natively, and the statutory reporting flexibility to handle several countries at once without a parallel system.
Where it frustrates people
This is a large commitment and the reviews do not pretend otherwise. Implementation is a year long project with a specialist partner, the cost regularly lands well beyond the first quote, and you will need internal people who know the system. Consultants who genuinely know X3 are scarce in North America and priced like it.
The interface is functional rather than modern, and the learning curve is steep enough that user adoption is a project of its own. Below roughly a hundred employees this is too much system, and the most common regret in the reviews is not that X3 failed but that it was more product than the business ever needed.