The Cadillac Escalade is the chief competitor to the Navigator and has a much stronger V8 engine and comes with a nicer interior, but costs more and the third-row seats do not fold flat. The Lexus LX570 also has more power and a beautifully finished interior, but also lacks a flat-folding third-row and doesn't have as much interior room. The Mercedes-Benz GL-Class is more agile and offers an efficient BlueTec diesel option, but doesn't have as much space or towing capacity and generally costs more. The Land Rover LR4 has a more powerful V8 and standard four-wheel drive, but doesn't have as much space inside or as much towing capacity.
While competitors offer more power and luxury features, the Navigator excels at offering a combination of passenger space and ruggedness that makes it popular with people who need different capabilities. Even the most basic Navigator comes well-equipped and offers advanced features like SYNC and satellite navigation that even some competitors that cost more money list as optional extras. If you're looking at a large luxury SUV, the Navigator is still worth a look.