For several years, the GMC Acadia, Buick Enclave and Chevrolet Traverse midsize SUVs were much the same. This year, GMC is shaking things up with a completely revised version of the Acadia while the two other models remain practically unchanged. The Traverse sets itself apart with a spacious and versatile cabin as well as class-leading cargo volume. The only available powertrain is a 3.6L V6 with 281 or 288 horsepower, paired with a six-speed automatic and optional all-wheel drive.