August Wi-Fi Smart Lock is the upgraded version lock. Everything in the 4th generation is fine: smaller design, better grip, in-built Wi-Fi, and even the company recently dropped the price of this smart lock. Unfortunately, the company had to reduce the number of batteries inside the lock that may lead to worse battery life. It is not a good idea to choose August Wi-Fi Smart Lock by watching the only downside. You have to look at the overall performance of both the Smart locks.
Please read the originial post here: https://blogs-hunt.uk.com/august-wi-fi-smart-lock-vs-august-smart-lock-pro-which-one-is-better/