Yes, I get your concerns. My experience was:
  • for small payments e.g. 5-10 chf it took maybe around 3-4 seconds to confirm in my wallet and another 3-4 seconds to confirm in the merchant's terminal, which I found competitive with other payment methods.
  • for a larger payment of around 90 chf it took around 30 seconds in my wallet and around 15 more seconds to confirm in the terminal. That was at a table in a restaurant, so no time pressure luckily.
Overall the increase in delay is definitely noticeable as the payment amount increases. What I also have noticed is, that the delay can vary from wallet to wallet, so maybe you want to start with small amounts in the 10 chf range with different wallets and slowly work it up from there.