I've been an Executive member for 3 years. I'll try to help;
First, when you book your rental, choose full size, not intermediate. It may show a higher rate, but once you choose it, it will show the same price as an intermediate car.
When you go to get your car you can choose from a special Executive Aisle, which will have full size or larger cars only. You are guaranteed a full size car.
You can choose from the Executive Aisle, but you can also choose from the Emerald Aisle, so your choices are better.
Instead of needing 7 credits for a free day, you only need 6 credits.
IF you don't meet the guidelines by the end of the year (40 rental days) you will drop back down to Emerald Aisle and your account will be changed and another new card will be sent to you.
For the poster who asked if they need to book under Executive Aisle, yes, your confirmation will actually say Executive Aisle. If it does not, you will need to go to the counter because there may be issues when you try to leave the garage. You could try calling to see if they can add it to your reservation.
The hang tag on the mirror will say EXECUTIVE not Emerald, this way only Executive members can select these cars.
For the poster who asked about the minivan. Getting a minivan is always a gamble, but as an Exec. Aisle member, your choices are twice as good that you might get one. If you NEED one you still have to use Emerald Reserve.