After much research, I purchased the iBoards for my 2016 GMC Sierra Silver DoubleCab. The running boards were easy to install and solidly attached to my truck. I chose the 4inch boards due largely to the small footprint and style. My only feedback is with Running Board Warehouse - the box was missing 2 bags of flat washers and lock washers. Luckily, I had plenty from my own personal stash and was able to complete the installation. Since I've previously ordered running boards (for another truck) from Running Board Warehouse and the order was perfect, I'll chalk this error up to: simply an error. In summary, good company, fast delivery, high quality running boards - my truck looks and functions great! PS: I had all-but-completed the order for AMP Research boards and decided to try these - I'm thrilled with the choice (1500.00 vs. 190.00).