I installed this the weekend after I got it, was easy to install. I have 3 sides of my house covered and part of the living room covering the entry. I am happy with the quality of the video day and night. Could use more light for the night vision but knew what I was getting. The recorder does well and bringing back recorded video is easy. I also love checking on my kids when they are in the living room when I am at work. I can call them and tell them to wave at the camera so I can see them. It is great. My complaints are the motion notifications are worthless outside. Bugs and mist set it off so I get hundreds of email notifications a day with the sensitivity set to 1/ lowest. The app stopped sending me phone notifications so I only get email ones now. Also when my internet goes down and I reset the router the DVR also goes offline until I reset the DVR also. For the money even with the cons, I am still very pleased with it all.The DVR software is a little confusing at first to navigate, nowhere in the book does it tell you that if you only want motion recording that you have to click "stop recording" on the main page. Once you work out the quirks of the software the camera system runs great! The Application for the Andriod runs well, and the application for the PC works great too! I had it installed for almost a year and lost two channels, I thought it was the cameras going bad but the DVR system had gone bad. I contacted customer support and worked with Slina. After some troubleshooting tests, a replacement was sent to me and I was back up and running in about a week. Good customer support and no hassle on getting a replacement when one was needed!One star was taken away for the first failed device, but I would absolutely still recommend these.I would have given them 5 stars but there is no instruction on how to record, all the instructions we Asian and I couldn’t understand themI give it a 4. One came in broke and I didn't feel like sending them back, other than that their greatI got the 4 cameras without the HDD. For what I paid for it's excellent. The picture is vary clear in both day and night. I was fearful of low quality because of the price. The draw backs and the reason i didnt give it 5 stars are that the camera top plate falls off very easily, so be careful when installing. Another draw back is that the cameras can not turn right nor left so some of your videos might be side ways. What i did about the memory part was I thought the 500 gb internal hard drive because it was the one that made the most sense and most reasonably priced. It was really easy to do, just open the dvr box and just plug it in. Really simple and they have videos on how to do it.Customer service was very good, especially with the person who helped me. I can not give this unit a 5 star even though ever problem was taken care of.(almost). Customer service is by email only but they respond fast.The night vision of the cameras is so good i had to check to see if the outside lights were on. The problem with this system is the Zosi View app does not work. After reading the permission this app wanted i am glad it did not work. This is very scarry a app from a foreign country wants these permissions. I would only recommend this unit if you do not want to check it on your smart phone. If you want a stand alone unit that records with the excellent cameras, i say buy it.Haven't used for a long time but definitely seems like a good system the power and video cables supplied are definitely long enough to get to most places video is very clear and easy to set up only gave four stars on night vision because I would like to see a little more distance out of the infrared lighting but overall a very good system especially once you add the external hard drive mini auctions for customization and alarmsHe comprado varios sets de Zosi para mi casa y la de familiares. Su precio es muy bueno y la imagen también. Mi problema es que la aplicación no es muy “friendly”. Hay que abrirla y cerrarla varias veces. Las cámaras tienen excelente imagen de día y de noche pero el material de la construcción desmerece rápidamente y tienen a recibir humedad por dentro muy fácil. En mi caso las limpio cada vez que pasa pero es tedioso.