I'm mostly satisfied with the performance of this DVR, it has been reliable and does not crash. I upgraded the HDD which was a simple matter and have been using it for over a year, so it does the job. I generally access it using the android application which I have not had any problems with. The DVR features work well and are responsive enough so all good there.I have run into some things I think worth mentioning though, some are small issues and some could be more important:1. I was only able to get remote access working with Internet Explorer 11 or Amcrest Surveillance Pro (and the android app). It does not work with Edge or Firefox, but they say it can work with Chrome using a plugin. Unfortunately I had no success with the Chrome plugin (see pic). They said they are working on getting support for more browsers however.2. To set the detection zones up, you paint the camera view with different colors (red/yellow/blue/green) by clicking on boxes with the colors and painting. Seems simple but whenever I need to make an adjustment on a camera, I have to check each of the other color boxes individually since each one seems to have a different idea of whats going on with the zone. I still have not figured this one out.3. The DVR can be set up to send emails on alerts, but the pics it attaches are really small pics (352 x 240) and almost useless for identification. I have not found any setting to have it send larger pics.4. I did manage to get locked out and found their password recovery process very strange. There is supposed to be an option to use pre-configured password security questions to reset the password, but (although these were configured and I had the answers), that method did not work since there was no way to enter the answers from the login screen (connected via HDMI with a USB mouse). The other method involved sending an email off to a domain which was not even amcrest.com, with a key based on a QR code (see the pic). I decided instead to just factory reset it which required opening the unit up and pushing a button on the main board while it booted up. My bad on the pw typo, but just hope you don't need to reset it.5. Setting up IP Cams on this unit requires setting a channel up to support them (management > Camera > Channel Type) and then disable a channel and change it to "IP". Then, once the channel is set up, the IP cam's parameters are set up in management > Camera > Registration. Since they sell IP cams, it seems odd they don't make it easier to add them.6. I had a problem with one machine which had previously been able to view the cameras using IE11 no longer showing any camera views. It also would not allow me to re-download or re-install the plugin from the DVR (guess it detected the plugin was still there, though it was not working). I found that to fix it I had to stop the process using task manager, and then run the uninstaller in "C:\Program Files (x86)\webrec\Torch\4.1.63.0", then delete the remaining file for "Torch". Doing that allowed me to re-download the plugin for IE11 (this worked for me, so no guarantees if it will break something else). I think it would be helpful if Amcrest made the plugin a separate executable that could easily be downloaded from their site, with an uninstaller, instead of what seems like an automatic process to trigger the ability to download the plugin.7. To download firmware they made me give up my email address - every time, which is just bit odd since I already have an account with them and thought I was signed in. This seems to be an amcrest thing though, they really like to have your email. Upgrading the firmware however was easy, but even though it can apparently be done from the webUI, the info I read recommended that it is done using a USB thumb drive.8. There does not appear to be any integrated cloud backup available for this unit yet (FWIW their website says it is planned). FTP backup works but there is a lot of data generated and setup is not intuitive. It requires setting up days of the week and times for every channel, when all most people will want is to backup video when there is an alarm / motion detection. Really need to get the alarm detection tuned to use that feature too, but FTP is one way to work around the lack of cloud backup.I also tested out the Amcrest Surveillance Pro application and it works, but is clunky to set up. I really prefer a webUI and hope they get support for Edge/Firefox/Chrome soon (not a fan of keeping IE11 around).To be fair, no DVR I have used has great software (I am no expert though), so Amcrest is probably above average in that regard. The software is pretty stable on the DVR, just "quirky" to set up. Their support is decent but offered me no good answers I had not already tried, since the issue I had was related to browser support - and that will be up to the developers.Overall, I may buy this again since I now know the downsides, and have some workarounds for it's limitations, or can live with them. The biggest issue is still the lack of an integrated cloud backup option and support for Edge or Firefox (and in my case Chrome since I could not get their plugin to work for Chrome). As a Security DVR it is reliable, and the basic features required like playback and storage work well. The Android app is also functional and does what it should, however I would not advise making this DVR visible by port-forwarding,. If you need to get remote access, a VPN would be a much more secure way to go.