I've never tried an Eclipse but I have owned a couple of JVC's. They work decent and are reliable but menus and control are horrible. You almost have to pull over and stop just to make simple adjustments like turning down the sub volume.

USB control works decent but is a little slow and doesnt recognize subfolders.
My unit is an older KDG-820, but quite similar to the newer models.

The preouts on my HU are a little weak IMO. The output for the sub is significantly weaker than the other 2 outputs. It can be compensated for by adjusting gain levels on my amps, but WTF did JVC design it like this?

And... satellite radio doesn't work worth a crap on the JVC.

 

Yeah the controls are crap on my JVC. The Eclipse CD5030 looks easier to use...