I have been using Blue Iris for about 18 months with 5 cameras and can recommend it.
I use motion detection to record clips to disk as well as the iOS app for remote viewing and get email alerts when a camera is triggered. I don’t do continuous recording.
The only problem I have had is with spiders triggering one of the cameras but that isn’t the fault of Blue Iris.
Make sure the machine you intend to run it on has a sufficiently powerful CPU and adequate RAM.
Take a look at
https://ipcamtalk.com/ for discussions on Blue Iris and hardware configuration.