The 2013 GMC Sierra isn't quite as comfortable as some of its direct competitors, although cabin quality remains top-notch across most of the model lineup.
Rather flat, wide, and unsupportive front seats are at the root of why we find the Sierra not to be all that comfortable--especially for longer trips--even though they do fit wide folks quite well. Crew Cab models also have a back seat that's more thinly padded than expected, with a seatback that's too close to vertical. Six-passenger versions have a higher, more workmanlike dash that leaves enough space beneath for a middle passenger to find decent leg room.
The Sierra can also be configured as a five-seater, one with a large center console that splits front passenger space, while it also give the dash a more upscale appearance. Big controls and clear displays make the Sierra's climate and audio systems easy to decipher.In back, there's less good news.
Three different body styles are available, as well as three different bed lengths (4'-8", 6'-6", and 8'), with the standard Regular Cab having very little space behind its front seats for anything other than narrow objects. The Extended Cab gets a bit more room--enough for gear and tools--and a pair of rear-hinged access panels to make that space more accessible. Sierra Crew Cabs have four front-hinged doors that can accommodate up to six passengers.Road and wind noise are quite low, either compared to other full-size pickups or to previous versions of GM's trucks. And throughout most of the lineup, materials feel better than utility-grade, with high-end versions offering richer trims.