Quite a difference ay!!
We have all looked at the cabin pictures and seating plans - are both carriers selling C class cabins officially?
I'd say that EOS is more comparable to VS Upper Class and MXJ to VS Premium economy.
Me thinks this is the basic idea - it would be stupid to serve the same route with exactly the same product. EOS certainly targets a different clientele than MAXJet - the ones and the likes of those who used to fly Concorde one the one hand while Maxjet those who are fed up with the Eco experience but are not willing to pay legacy carriers' biz fares.