[quote]What advantages and disadvantages do the Halo and Mass Effect universe have against each other?[/quote] Neural physics. The Precursors had technology which was literally immortal, only Halos could destroy them because they cancel out the principles of neural physics. Star Roads were used to link whole solar systems together, push suns through space, displace whole fleets into alternate dimensions, dilate time and space, block slipspace access, or just smash entire planets apart.