Not this particular model but other Dahua PTZ's and I can tell you that they are very good both in quality of image and value. I have 5 up now at one location and the customer has requested another one. 5 outdoors and one indoors with very high ceiling. I love them.
What models in particular do you have?
Pro Focus LLC | 07/20/16 01:55am
While I don't have any experience with this particular model, I do have experience with Dahua PTZs as well as their fixed line of 4MP cameras. I can't remember a single issue that I have encountered with the latest PTZ I installed, it looked exactly like the same style as the one you linked above, but 1080p CVI instead.
The one issue we have had with the 4MP line of fixed cameras is a bug in the firmware that allows unauthenticated users to access an RTSP feed via a web browser, which also changes the camera main stream setting to MJPEG and max bit rate and frame rate. Here is a link to that post.