Watch: Engineers 3D Printed a Model Jet Engine, Then Started it Up

Probably. Traditional machining processes have become very efficient due to the enormous industry and many years of innovation. I think the more important part there is "more complex parts." You can have arbitrary complexity at no additional cost, which is really cool. Now you can do cooling fins and support ribs and impossible snaking holes* and all sorts of stuff without needing additional machine setups or tooling.

* such as the fuel injectors for some GE jet engines, which can now only be made using this technology

if you're starting with a block of aluminum or a bin of powdered aluminum, then yeah, the tooling for machining the solid block would likely take less energy than the laser used for sintering the powder.

However if you take into account the energy necessary to cast the aluminum block in the first place, the laser may be more efficient. But, for all I know they take cast aluminum billets and some how shred/powderize instead of making the powder as it is refined.