The reviews I've read for these products say the app you use on the phone is seriously flawed to the point of not working.
Of course that can be corrected on any given day with a new app version, but it's something to be aware of if consider buying.
FYI.
the older models were laggy but the newer processors are better. maybe the internals of the cameras themselves are better too, im not sure. i also bought a high end router with mimo at the same time although that would only help with streaming speed.
it takes me about 5-8 seconds for the app to boot up and video stream to start. used to take 15-20 seconds to load and sometimes not all channels would stream so youd need to reload the stream.
the streaming video is on a 1-2 second delay which some people seem to complain about. im more annoyed that you cant just pinch to zoom, you need to first scroll to the right and then click digital zoom to be able to pinch to zoom.
you can take snapshots and manually record something if you have it set to motion sensing activation, but
viewing recorded video on the app will freeze the app. this is probably what people complain about but to me its not a big deal. viewing video thru the app is only in 360p so you cant identify much anyway. id rather view it from a 60" 4k tv at full resolution.
i think for most homeowners the factory programs are 'good enough' and simple enough. but if you have an elaborate house or a retail/office that needs surveillance id definitely go with blue iris for the added features.