I’m sure being an electric the 0-15mph time will be as quick as any 1.0 litre petrol.
Speed is normally linear with an EV.
Its not going to win any competitions but, if all your after is a city car to potter around in, the Spring will be adequate. On the otherhand, if you plan on going from Lands End to John o’Groats, charging stops will be longer than the actual journey time!