My iPhone X has been great last couple days here in Toyko. Added my Suica card to my Apple Wallet, got the 500yen deposit added to the card. I can add funds via the credit cards in my apple wallet or with cash at the machines. The machines only take cash and I'm not aware of anything official that takes credit. You can buy a new card via credit card with the funds loaded on 3rd party sites but you will pay a bit extra.

Topping up with cash sounds a heck of a lot easier if you don't have a compatible device.