Anitajs,

Thank you for your question!  There are a lot of variables that affect this answer.  One of the biggest questions is the manufacturer of the cameras you already own.  Many camera brands really work best running on their native platform (particularly IP cameras, which I assume are what you have as you were tasked with researching an NVR) so if you already have 40x Dahua cameras for instance you're probably better off sticking with that platform in most scenarios.  Having to rely on the vicissitudes of ONVIF compatibility can be a bit of a frustrating experience.  

VMS platforms can be a good option, but generally provide the most value to multi-site deployments or massive systems pulling in 100+ cameras.  Many of the highly rated VMS platforms with charge an annual licensing fee per camera, others a one time fee but generally you won't just be paying for just the software, you'll also have to pay to use it.  You will need to research what features your cameras support are also supported by the VMS for that camera and then there are the costs of the network infrastructure/server solution you need to dedicate to running that VMS.  If you have a wide array of different camera brands and they are well supported by your VMS of choice, it would be an option to consider certainly, or if you have many different remote sites or a massive amount of cameras you want to be able to monitor/interact with in a single location.  

Our 64 Channel Elite NVR has native support for heat-mapping and people counting, and with it's latest NVR 4.0 firmware also allows support for Facial Detection/Recognition with metatagging data such as facial features when used with our latest AI powered cameras (https://www.securitycameraking.....lt-in-mic/) .  The metadata can then be searched through with the AI search feature to help reduce the amount of time you spend searching through footage to find precisely the information you are looking for.  Do please note that AI features are limited to our Elite cameras, and it is not a feature you can enable on every channel (24 channels max for the Facial Recognition, for instance.)  

I hope this gives you some jumping off points for your inquires.  Please feel free to reply here for more meta questions; if you have specific questions about our product lineup and how we might be able to design a system to your needs please feel free to call us at (561) 288-5258 ext 2 for sales, or you can reach me directly at ext 137.