For that application, where it seems you only seem 720p/1080p video, you might be better off with a TVI/CVI/HD Analog type of system.
IP is going to have some inherent delay, not sure what a tolerable delay is for you or how much you're willing to spend. You *might* be able to drop a couple hundred ms by switching to a PC with a lightweight VMS instead of the DWSpot adapter, but I'm not sure. It might also help to adjust camera settings to see if you can tune the video stream to something the spot adapter can more easily decode. Maybe decrease bitrate, play with quality settings.
Related test: Testing IP Camera Latency. Presuming the network is not overloaded, it probably has to do with the client software / station. As such, I'd ask DW. I've forwarded this to them for comment.
What's the latency when viewing the cameras directly from Axis client with nothing else running? Try client in MJPEG mode.
I have never seen >= 1 sec latency (unless something is misconfigured) in an Axis camera in this config.
If you still have the latency, connect the camera to your PC using a crossover cable and a passive POE splitter. Let me know if you need additional details on this.