The whatever has a flex rating of 7 (softer side of scale) and has an extruded base with bi ax laminate (reason for softness and/or 'whatever'). The evil twin is given a little more care and core. Tri ax laminate with a flex 6-7-6 (softer in the middle) and sintered base (faster). MSRP difference is that the ET is $50 more. The Whatever seems like the replacement for the old Goliath, that is now tri ax all around and straight up sintered base this year. Yeah 4 that. Whatever seems fun, but it's name has been ironic for how it makes me feel- 'whatever'.
I vote ET based on design and structure. Your riding style/ location/ and experience will help determine how it matches your interests.