For me with Turbofins and relatively flat water, the Revo 13 has a "fast" (one hour) cruise of about 5.05 MPH+/-; The Outback and PA both log in at about 4.8 MPH. You can use these figures for relative
More specifically (using constant power from the Torqeedo electric drive), the Outback builds about .5 MPH speed advantage at about 4 MPH, but the difference mostly disappears by about 5 MPH when the Outback is starting to push a lot of water. At about 3 MPH (where most people cruise) there is approximately a difference of .2 MPH difference in favor of the Outback. Weather conditions can change the picture though.
Actual performance is affected by wind and chop, Drive condition/tuning, and seating position, not to mention individual differences.