I'll tell you that Apple Pay is significantly better if you have the watch. Since the watch is already authenticated to your phone, there's no fingerprint mess. You just double tap the side button and hold the watch over the payment terminal, it taps you, and you're done. It's extremely convenient.

For extra oddness, Apple Pay is extremely fast everywhere I've used it except my grocery store. There it takes about 30 seconds. I have no idea why. The device tells me I'm done, but for whatever reason the software on the point-of-sale system doesn't decide that the transaction has been paid for for a surprisingly long amount of time.

I've timed it at the WF next door and it is ~13s. Not "tens", but significantly more than your "max" of 10.

In my experiences it's between 10 and 20 seconds. The places that haven't yet updated their terminals and still swipe cards are much faster.