What's the difference between a Bluetooth/smart lockbox and a standard combination one?

Standard combination boxes use a 4-digit code you set manually and reset by hand. Smart units such as the igloohome Keybox 3 and Master Lock 5441EC add app control, shareable or time-limited codes, and access logging, which is why Airbnb hosts and businesses gravitate to them. The trade-off in the consensus is higher price, dependence on batteries and an app, and more reported reliability complaints.