What is the difference between outdoor cameras W2 W3 and W4 ?

Here is the main difference between older W2/W3 and W4 camera :
W2/W3: supports RTSP, ONVIF, NVR, and third party softwares. Doesn't support Cloud Storage. Motion detection function is not great or sensitive. Cannot get alarm notification on IOS devices. Use Wansview App.
W4: supports Wansview Cloud Storage. More accurate and sensitive motion detection. Doesn't support any third party softwares or web browser. Can receive notification on both IOS and Android devices. Use Wansview Cloud App.