It is not about the product
Most coating failures are not product failures, they are installation failures. The same epoxy can last twenty years or fail in two depending entirely on who installs it and how. That makes the contractor the most important decision you make.
Ask about surface preparation
This is the single best predictor of quality. A serious contractor mechanically prepares the slab, shot-blasting, grinding, or scarifying to the right profile, and will tell you exactly how. A contractor who plans to acid-etch or just clean and coat is cutting the corner that fails first.
Ask about moisture testing
If a contractor does not mention moisture testing, walk away. Moisture is the leading cause of coating failure, and any professional tests for it before quoting a slab on or below grade. The answer to this one question filters out a lot of bad options.
Look for documentation and the right system
Quality contractors document their work, prep standards, mil thickness, test results, and specify a system matched to your actual service conditions rather than selling one product for every job. References from similar facilities and proper insurance and safety records round out the picture. The cheapest bid is rarely the cheapest floor over its life.