Those who dismiss the Rainier as little more than a GMC Envoy in Buick clothing need to look a little closer. While it's true the Rainier uses the same engines, transmission and chassis as the Envoy (and its cousin, the Chevrolet TrailBlazer), Buick has given its midsize SUV a number of features befitting the nameplate's upscale image. A premium interior includes standard perforated leather seating, dark walnut dash appliques and power seats, while underneath the Rainier resides a standard load-leveling rear air suspension. Compared to traditional steel springs, the air suspension not only makes the Rainier's ride smoother, but keeps it sitting level, even when loaded down with crew and cargo. When equipped with the six-cylinder engine, the five-passenger Rainier provides good power and reasonable fuel economy.