One minor distinction about the DXR-8 is that it comes with two interchangeable optical lenses (a standard lens and a zoom lens) and you can also buy a wide-angle lens. Having three different lens options is nice, but in practice we felt the zoom on the standard lens was sufficient, and we expect most buyers would probably not bother changing the lenses frequently, if ever.
It really depends on what you feel most comfortable with. There are audio monitors that allow you to listen to any noise coming from the nursery, vital monitors that track sleep and breathing and video monitors that add sight to sound. Babylist parents overwhelmingly choose video monitors. The security of seeing what your child is up to—like if they’ve gotten tangled in their swaddle, pulled their diaper off or climbed out of the crib—can be worth the extra cost of a video monitor.