The construction feels solid. Some of the instructions weren't completely clear, but everything turned out fine. 
The shelf system itself just sits in a "hole" under the staircase, which isn't terrible, but isn't as secure (it's not bolted/screwed down to anything). The magazine rack is about a quarter-inch too narrow for the opening, thus the screws are slightly visible. The paint itself is okay, but could have been better (I ordered white). 
The delivery service really messed up! They gave me part of someone else's package, and must have given them mine. My wife was the only person home at the time, and did not know what to check for. However, Wayfair's customer service was excellent, and they sent a replacement right away.