I just returned a Lorex NVR/Cam system and built a BI computer. Amazed at the flexibility of BI compared to the NVR as no longer have "moth" events other than a rare one every other night or the "headlights shining in motion area" events as cars turn the corner. Yes, the dedicated BI setup is a little more expensive but I am happy. 95% setup as a couple of issues still trying to resolve - one of which can't but trying to get creative. Also, the IOS app (and presumably android version) is phenomenal compared to what experienced with NVR. There is a reason those NVR IOS apps had a 1 star rating on the App Store.
That said, NVR's work and they are simple as they mask the camera and simplify with their base software not using all of the camera features. When shopping for a NVR, one of the biggest surprises was NOISE! So much so that I documented it with this video.
NVR noise There is a workaround. Try to find an NVR meeting your need that DOES NOT have power supply inside the NVR - typically look for a fan coming out the back. That is the noise culprit. Better yet, an NVR that doesn't have the ports coming out the back (which is what the power supply is for) and use a separate PoE switch that connects to the NVR. The internal port/NVR and the PoE switch + NVR cost about the same. Within Dahua model numbers, if the model number has a middle group, it has an internal power supply with ports. For example
NVR5216-4KS2 no ports, but firmware limits to 16 external ($268), and the similar model NVR5216-16P-4KS2, the "16P" indicates it has 16 built in ports ($334). I only needed 8 ports with the BI build and would also work with the no port NVR and got the Dahua 8port PoE PFS3110-8P-96. and can't speak highly enough about it. 1) good power distribution, 2) NO FAN SILENT!, 3) Dedicated uplink port so all 8 ports are useable. Coupled with that, my BI build is totally silent - particularly after I swapped out the CPU fan with a more efficient silent model compared to Intel stock cooler that comes with the CPU.
The NVR software is useable and perhaps over-simplified, it was the IOS software that was a royal PITA. When I was in Europe (or locally at the office) I had no problem establishing a VPN with my laptop and accessing the system. Irrespective if BI or NVR would strongly look at upgrading you router if your current one isn't VPN friendly.