I work for a Hikvision dealer and I will tell you now, thier tech support, like others, are not as skilled as me. When I first was starting out, I called them once and once only because I put a new 4mp fisheye on an older hikvision installation (5 years old) at a body shop and wanted to quickly need the settings so I didn't have the "No resource" issue. Needless to say, I could have figured it out myself because they didn't know off hand and I went thru a trail and error with modes with the support guy that barely spoke clean English. Needless to say tech support with camera OEMs is always sketchy. I even have to submit sometimes the password reset form for a NVR 2-3 times after waiting an hour. Sometimes, I submit one and the next day I get the reset email so , its not so end user friendly. Even for a dealer installer. On cams, I find breaking out the ladder and manually reset them is less fustrating than going thru the reset wait that sometimes have to resend the submission form online.
The difference between getting ones off the bay and amazon and a dealer is most of the ones sold outside of a dealer are factory seconds that are not in the warranty database of theirs. But rarely had to replace a camera because of failure and those failures, the cams were installed 5+ years ago and outside cameras that are subjected to sub-zero temperatures every winter. If the camera works, it works.
I have been called out to people's houses from time to time of a hikvision system they got thru online sources. Most of the time, they bought an older NVR that don't support the high MP cameras well, or its cabling/network issues, or had too many whistle and bells enabled that never worked well in the first place.
