When David Page announced pgAdmin 4, I was really excited to try it out. I was impressed I could compile it so easily on windows. I had a few bumps, but not too bad.
One of the reasons I'm excited about it is that it's built on Python and a web framework, and there is a large Python and web developer following in the GIS community, so I suspect someone will step up to the plate to add a mapviewer plugin to this so I can have a seamless PostGIS experience.
The interface is also very slick and pretty and I love the sorting and paging capability now in the query window. Check this sampling from our workshop database.