I think is it more important to have their credit card than the executive membership. It is a huge advantage if you plan on buying any electronics from them. We bought our TVs from them, and they ended up extending the warranty to 7 years. The unit had a three year warranty, the standard Costco Warranty extends it another 2 years and the credit card extends it another two years. If I have any problems with the TV before the end of 7 years, they will give me a new one. Can't beat that deal.
The credit card also extends the warranty on other purchases like ipads by one year.
Eyeglasses are super cheap there. So are tires and batteries. Their gas prices are good saving 3% on travel expenses like rental cars was amazing back in the days when we could travel. This discount is available no matter which membership you have.
The credit card has no annual fee and is a good ideal if you are in the market for electronics or travel a lot.
In order to get the extra $60 back for the executive card, you must spend $3000 per year at Costco and some purchases like gas and alcohol do not count. If you think you will spend less than that at Costco, then the basic $60 card would be better.