The 6AE830VNI is one of the most popular Dahua PTZ's that Andy is selling right now he said.
It is over a year old and is a great camera.
It may take a while to receive it.. last he said was 4-6 weeks out.
What I don't like about the cam is the slow lens focus and clarity at full zoom. (maybe I just got a bad one)
At 4k I have some frame skipping after recording for several days.
I don't know if it from the most recent firmware or from the newest 5208 4ks2 NVR firmware it is recording to. It wasn't happening prior to updating,
so I'm thinking it is the NVR..
Everything else is
very good about the camera.
Dahua SD6AE830V-HNI sample
Depending on your budget and the need for 4k the SD10A248V is one of the best so far, but at $1600+ ouch !
Also the SD6AE240 has a excellent picture. ( samples a couple post down in the above link)