Now using a Chase Chip & Signature card in London, and surprised how slow the transaction verification process is. Estimate the card remains in the terminal 10+ seconds, then the receipt prints. In a couple instances I have needed to point out to the assistant that a signature was required.
The time for the transaction can depend on wide range of factors and can be caused by the card, the terminal, or a the combination of both. There is a lot of negotiation that happens between the card and the terminal.