I have been using this doorbell for about 2 months now and I am very happy with my purchase.
The night and day vision is very good and the motion detection works well. I had to adjust it down a little to minimise false alerts but it is fully adjustable from the app. The app is quite easy to use and you can download the recorded video and snapshots to your phone very simply (I was using iPhone). Best of all is no subscription costs but captured video is stored on the supplied memory card in the doorbell until you download it.
The included rechargeable batteries have been good so far, even with me playing around with it a lot during the initial few weeks they have lasted well. I have only had to recharge them once so far. It does take quite a few hours to fully recharge from dead but I just did it whilst I was home in the evening so no issues.
The pack includes both double sided tape and screws for mounting. I went with the screws to ensure it stays secured. You simply slide the doorbell up from the cradle to remove it for charging. There is a tiny screw in the bottom to hold it into the cradle if you need it to stop someone stealing it.
Overall for the price in comparison to the others I looked at, I would recommend this product.