Firefox Nightly is indeed much better CPU-wise, keeping 60fps with around 80% single core usage at most.

However, it still has poor graphics, with low quality textures, low/nonexisting anistropic filtering and no AA or bad AA.

Also just noticed that stuff like bracers that should be rounded (using GL 4 hardware tessellation) is not and has visible polygonal edges.

Not really a great showing as a demo.