Usually when I choose to go through the express line it is because the line is around the same length or barely greater than the other lines and there is a clear advantage because the normal lines have people with groceries filling their carts to the brim.

Something confusing me was the pleasantries exchange and cash is faster than debit. People do say hello and ask if you found everything fine and whatnot but while they are saying that they have already scanned 3 or 4 of my items I haven't ever had the trouble of someone talking and waiting for response before scanning items.

In response to cash is faster than debit there are always people fumbling with wallets to get cash out and such while with a debit card you just slide (most of the time before the checkout is even done) and enter pin/ sign receipt and you are on your way, you don't even need to wait for someone to count out change back to you.