Naga or Grim Reaper?

Naga is more rounded,has more weight, about a hundred less energy and 100 more hp.
Grim reaper will be destroyed by heat bomb mechs.
So it actually depends on what kind of energy build you want to make.
for anti energy and anti heat, use naga or even windigo.
For just pure energy vs energy, use grimreaper, but add a crap ton of hp plates and engines