Not so great -- at least in my wallet (all of which are no annual fee cards).
I get 3% cash back at restaurants from a different Visa card, let's call it Card B.
The Visa card from my brokerage offers 2% cash back on all transactions, regardless of merchant category or transaction type (Apple Pay, swipe, EMV, card not present).
Card A offers 3% at supermarkets and 1% everywhere else. Card C currently offers 5% cash back at gas stations this quarter and 1% for most other categories.
Card K and Card V have less exciting rewards programs but both have no foreign transaction fees. Card K -- from my credit union -- includes cellphone insurance if you use it for your monthly cellphone plan payment.
So my main usage case for Apple Card is Apple Pay purchases abroad (2% cash). However, since Apple Card doesn't export data to Quicken, Mint, etc., I have little interest in using it for small transactions, like a $5 breakfast at Tully's Coffee in Japan. I might consider using it for a $200 pair of shoes while traveling.
Here in the USA, I have even less motivation to use the Apple Card.
My iTunes purchases are funded by gift card redemption; you can periodically find iTunes Gift Cards on sale (particularly during the winter holiday season) at a 15% discount. Buy these on a 2% cash back card and you're really getting 17% back rather than the measly 3% from Apple Card for a direct charge.
Apple Card might have slightly better security, at least while using the physical card. It sure looks purty though.
Since they have been mentioned repeatedly, I looked at the Chase Sapphire Preferred and Sapphire Reserve cards. Very nice offerings at a price. The latter is comparable to an AMEX Platinum.
One thing, if you use an airport with a Centurion Lounge, you can use it if you purchased your airline ticket on the AMEX Platinum Card.
Many of the cards with annual fees are geared toward frequent travelers, particularly those who take a lot of international trips. Judging from most of the comments here at MacRumors and similar Apple rumor sites, the people who participate in these discussions are rarely the type who travel internationally because they rarely mention the "no foreign transaction fees" of the Apple Card.
Hopefully Apple/Goldman Sachs will add additional benefits in the future. I really need to see data export to Quicken/Mint/etc. before I will use this card on a regular basis. I simply don't feel that it is worth my time/money to monkey around with Quicken/Mint/etc. to manually record a low value transaction in those systems when my 2% everywhere brokerage card automatically exports this data.
I activated my titanium Apple Card and promptly stuck it in a binder with the other three cards I don't usually carry. I've made one Apple Pay purchase and already paid the balance due of ~$11. My next purchase will probably be in September, just to keep Goldman Sachs from thinking that I've forgotten about the card.
An inauspicious launch.