So far I have used two non custodial swaps or you say instant exchanges, that are running signatures on the forum and in my case I have got satisfying results in both, It took almost 30 45 minutes to complete swaps. And the two instant exchanges you mentioned may be very popular but I have not seen them running signatures since I joined the forum, so maybe they are less familiar to me.
And I am currently using a centralized exchange to swap coins regularly. But from what I saw on another forum, many centralized exchanges are freezing users accounts. So now I am trying to shift to an instant exchange regularly. Although the swap fee here is a bit high, I will try not to swap large amounts.
Instant swap exchanges are kind of new but the swap like changelly or ChangeNOW have been here for long enough and they don't need their promotions or not sure if they ever ran it here.
But instant swap exchanges are lot better and they just need one confirmations for btc deposit and instantly swap them to the required pair and the wait time depends on the confirmation time and blockchain, the swap is literally instant.