In New Zealand the legal power output for a road going electric bike is 300 watts. A 300 watt electric bike will go about 32-35km/h unassisted. Hence most NZ production electric bikes go about this fast. A 300 watt mid drive system like the Lekkie Summit can go faster as it is using the bike gears and human input to obtain higher speeds.
There are system available that can go much faster, but the bicycle must be registered to go on public roads.