As previous posters mentioned, EY has less scale than EK so that they have generally more trouble in fixing things when things go wrong (e.g., I have had multiple instances where EY delayed a flight in order to wait for an incoming connection, which I have never experienced with EK - since EK has several flights per day to most destinations, less need for them to accommodate such irregularities).

In general, as an Elite member, service is much better on EY. They recognize Platinums as "special" (as opposed to EK's generally lackluster attitude) - there are much fewer Platinums at EY. Also, it feels like flight attendants are more hand picked at EY.