The overall rating reflects the current state of the app. It accounts for all app reviews but prioritizes the most recent ones.
In fairness it works pretty good. Been using it for 3-4 years with reasonable function... when its working... its good. It can stop working occasionally but it gives you clear notifications of whats happened and its pretty easy to remedy. It pays not to rush the initial set up but there is trial and error required to get it humming along... Support has improved and is friendly and Lech offers a nice "human touch" to his communication. Ive had my ups and downs with CTO but overall Im still happy and still using it.