Almost every camera, and certainly the ones in these price ranges, the IR cut filter is mechanical and you can hear it in the camera when it goes from color to b/w. Anything mechanical is going to break at some point. And if the IR cut filter doesn't go out, the IR LED are rated at 30,000 hours and they will go out.
You could add more light to keep the cams in color. Those cameras still work during day correct? So add some light and keep some life in them.
But since you are researching, you will come across if you haven't already the newest claims of full color cameras. Do not be sold by some trademarked night color vision (Full Color, ColorVu, Starlight, etc.) that is a marketing ploy in a lot of ways lol. It is simply what a manufacturer wants to claim for low-light performance, but there are so many games that can be played even with the how they report the Lux numbers. They will claim a low lux of 0.001 for example, but then that is with a wide open iris and a shutter at 1/3 second and an f1.0 - as soon as you have motion in it, it will be crap. You need a shutter of at minimum 1/60 second to reduce a lot of blur from someone walking.
Check out this video at midnight. You see this and it looks like daytime and be like WOW I want that camera. But any motion in the frame and it is crap and will be a ghost blur. You notice they do not show anything with motion. I can make all my cameras look like this at midnight with no other light, but we want good motion video, not still images video. This is a very nice cameras with enough light at night - so do you have enough light at night? All cameras, regardless of what they are called, need light - either white light or infrared. Simple physics.
While this camera is not what we would call a consumer grade camera and this is a really good camera, it is these games that the consumer grade cameras of the world do to their camera to make it look good at night - but then a person walking by is a blur and people simply say well the camera isn't good at night. If you have the ability to change the settings, you can make it work. Just remember that every increase in shutter speed needs more light. So I can set mine to 1/250 second and eliminate blur at night, but then all that is visible is a 5 foot diameter around the camera IF I have enough light.
If your camera doesn't have enough light to stay in color, a 24/7 full color camera will not be of much good and now you have a camera with no IR and even if you added external IR, the camera will not see it since it does not have an IR filter.
