Metallic hydrogen - super space fuel

http://www.independent.co.uk/news/science/hydrogen-metal-revolution-technology-space-rockets-superconductor-harvard-university-a7548221.html

"It takes a tremendous amount of energy to make metallic hydrogen ... if you convert it back ... it would make it the most powerful rocket propellant known to man, and could revolutionize rocketry. That would easily allow you to explore the outer planets. "

For me, a fuel which allows a constant acceleration of 1g (+/- 20%) would be the way to go.

If this metal hydrogen fuel is dense enough, then maybe it can allow this.

Think about it.  If you can accelerate constantly at 1g to your destination, then:

    (a) the humans aboard ship experience earth gravity.  Eliminating the problems of weightlessness.

   (b) your velocity is constantly increasing, such that, you can get to Jupiter within a week.