I recently upgraded my Aqara U100 smart lock with the U400 on the front door and it has been worth the investment. That has allowed to me move the U100 to the back door and both are connected to the Aqara M3 Hub and Apple Home using Matter over Thread.
My primary reason for the upgrade was because of the new Ultra-WideBand (UWB) feature. This is especially helpful when my wife and older mother have their hands full and it’s 40° Celsius and allows family members to enter without worrying about fumbling for keys, pulling their gloves off to enter the PIN code or read a fingerprint.
At these temperatures nothing seems to work right, except the U400. Walk up, walk in. Awesome! #QualityOfLife #WinningWinter