I love the HP4, but I'm curious to know if there will ever be an update. Over the years, the only thing that bothers me about the current design is that all the headphone cables are sticking out of the face and makes my studio setup distracting/messy, and managing cables gets to be a hassle, which also limits where I can put this in my setup.
I understand the need to plug headphones in quickly, but I don't think most use cases call for the outputs to be so readily available at all times. If the outputs were on the back, it wouldn't be terribly inconvenient to look in the back of the unit to plug/unplug headphones. For most studio setups, headphones aren't as regularly switched around as inputs on interfaces, etc.
I've mocked up what a revised version might look like - would absolutely love it if the headphone outputs were on the back and the monitor level control was larger as well.