RTR is good no doubt. But i like EB better for their
-victory conditions (dunno, last RTR i played was 6.0..maybe this is also new for RTR)
-script
-21 factions
-recruitment
-government

and i somehow don't like RTR recruitment policy, last tiem i checked i had to wait 4 turns for a hetairoi....

still, I geus steh main difference is aproach:
-RTR just started modding and gradually upgraded teh version public...starting at 3.0 with just fixes. ending with 6.x including a lot of skin-fixes and historical fixes
-EB just tore down RTW and started all over, form the groudn up...wich enables them to overhaul everything, but also give sthem a lot of bugs....some perhaps unfixable(though i doubt it)