If you're a tiny bit OCD then the main problem with entering a pin on a pad is the hygiene factor. Do I really want to be dabbing the same keys that a thousand other people have pressed that day? I suppose you could use a key or something to provide some physical separation from the filth magnet that is the key pad.
I'm only being half serious really. There is a marginal convenience and time improvement with contactless in my experience and as a result it is my preferred method.
As far as I can see Apple pay is completely pointless for the following reasons:
1. I have to carry my card with me anyway in case I wish to make a purchase at a store which does not have a contactless reader - presumably this problem will diminish to zero ultimately
2. My card has no battery to go flat, is relatively small (I don't carry a wallet) and therefore easy to carry. I can leave a backup (different) card in my bag too in case I lose my main card.
3. My card is free (effectively) whereas an iPhone is really rather expensive.
In short I think it will be a long time before I leave the house without a credit or debit card in my pocket and since the contactless card is already very convenient I don't see the need for Apple pay other than as a novelty.
I'm completely ignoring the security points in the article here obviously, but this is just the way I see things.