One of the major differences is using a rechargeable lithium battery which is chargeable via the USB-C port. If the Padlock 2 battery is flat, you can charge it using a power bank instead of a 9V alkaline battery.
It seems that igloohome gave me what I requested for. Even the product name is spot on.
Two years ago, when I reviewed the Igloohome Smart Lock, I mentioned the following: