Hi
@guitar
The answers to your questions are below:
Is the Incoming Bandwidth limit only important to IP cameras? --- Yes
Does it have any impact on analog cameras? --- No, the analog cameras are just a basic video signal sent over COAX cable (like the signal to your TV) and that doesn't really change, IP cameras convert the images from a camera into a data signal and the amount of data sent can fluctuate based on the resolution of the camera and how busy/complex the scene is.
Does it mean that the second XVR will have a clearer image from a 4K IP camera? --- Yes & No, on max. settings an 8MP IP camera is probably going to use something like 10-15Mbps so if you fully load both of these recorders with 8 x 8MP IP cameras you would likely need to lower the stream settings (e.g. resolution, frame rate, compression, etc...) on the model with the lowe bandwidth limit to stop the IP cameras from exceeding the recorders bandwidth limit. So in that scenario, the 64Mbps model would give you lower quality images than the 128Mbps model, but if you were only adding 1 to 3 8MP IP cameras to both these models you could could set max. settings on all the cameras and get the same quality images on both recorders.
Basically, the bandwidth limits will only come into play if you are planning to add more than 4 IP cameras, which if you are planning to add that many IP cameras you would probably be better off just going with an IP NVR (Network Video Recorder).
In general, what are the differences between the two models? --- The only other difference I can see from the spec sheets is that the Pro 4K recorder gives you more Encoding Capacity, which means you can run your higher-megapixel cameras at a higher frame rate than the value recorder. We have never handled/sold Dahua recorders so you might be better off asking this question directly to Dahua support or to the company you are planning to buy the recorders from.
