Off chain transactions cost you zero confirmation.
For faster payments we already have lightning which is pretty cool.
Does that come with additional costs ?
Transactions in the LN are cheaper compared to the normal transaction that we do, so it cost lesser than the usual ones that we do in the Bitcoin network. As we can see right now, network isn't that congested and clogged at all so we should just enjoy the cheaper fees that we have. But I understand that it's about the zero confirmation.
The problem with on chain is that it is unpredictable. If you need to make a fast transaction, you should avoid on chain and use lightning. If you happen to have an unlucky day, you could spend 1 or even 1 and a half hours waiting for the first confirmation. Whereas with LN either it works and a route to the other side can be found, or it does not work perhaps due to liquidity requirements if you are doing larger transactions. However, you will find within seconds or at most a minute whether it worked or not.
I personally never had any issues with reasonably sized transactions on LN. It is perfect for when you have to make a fast transactions of low or medium value.