We've only had the purifier for a short time. At first I bought just one to try it out, but the app and the settings are so cool that I bought three more. Like really, you can set it up any way you want. Even the "arrive" or "leave" function at a designated location, which they have in beta, works very reliably and always. This setup has never failed either. The purifier options are really amazing and if you buy one for 4,000 or two of these, then definitely two of these. I have others for many times more money, but they don't compare to these. The only minus is that it is impossible to sleep. Or it will, but it really is in the absolute silence of the night to hear them. However, it can all be solved with an app where I have it set to turn off at a certain hour and minute when I most often go to bed. And at 6.30 in the morning, he turns it on. Because of our daughter, we even have two in the living room in opposite walls and it's moved (it's squeaking on the dust). Yes, it's already a hassle to have two in one room, but really these cleaners have helped my daughter 💪 plus I can always put the other one in another room if needed. The only thing I would probably criticize, so the purifier, as it is conceived, sucks in from the back and blows out the top. But I guess we all have purifiers against the wall, who puts their purifier in the middle of the room like in the picture? So it just flips over, or the front panel is actually against the wall 😀 I have the display permanently turned off anyway though, because it's useless. The suction is great then. It sucks in the whole side from the room and blows upwards, so the purifier does not get stuck in the room and circulates the air perfectly. The comrades at Tesla might think about that, sucking from the front and not from the back. For example, my other Rohnson 9600 has the intake solved well, only the exhaust is wrong again, and it is slanted. But even so, it can't compare to this one from Tesla in the ability to program and set up the purifier via the app. For me, definitely three in each room for 7,500 rather than one for 7,500 in one room. I'm really very satisfied. And if you don't want this one, definitely go with Smart. The stupid ones (even on auto mode) that you have to manually turn on/off every day, you'll eventually put in the closet anyway and prefer to get one with an app and settings. I already have one of these in my closet 😁Another plus, when you put auto mode, they have ppm limits set to a certain flow rate by default. With this purifier you can change them. That's really cool when you request to lower the limits for the slowest speed from say 60ppm to say 10ppm and generally change the limits to "tighter". The way to do this is to set "when changing state" in appl, select ppm and set "when less than 10ppm, fan speed low. When 10-20ppm, fan speed medium. Etc. Nothing complicated and it works great 👍 Otherwise if you want to have more, for pairing the second/third,:. The cleaners in the application need to be turned off. Otherwise, I have not been able to add a new one.