The heat treatment of a blade includes (basically) :
1) a soak, get the blade very hot, raising it above the critical temperature
2) quench, get the blade very cold, very fast, usually by dunking it in oil or water
3) tempering, get the blade between the above two temperature extremes
Tempering can be done once or many times, usually one to three. Additional tempers have many effects such as grain refinements, increases in wear resistance, toughness etc. . How much of an effect is dependent on the steel and other factors of the heat treatment such as the use of cryogenics.
In short, additional tempers should make the steel better, but how much is difficult to say because it is dependent on the steel and other factors of the heat treatment. It can also degrade the performance in some cases so the issue is a bit complicated.
The maker / manufacturer should be able to provide more details as hopefully the blade would have undergone some kind of testing in the evaluation process.
-Cliff
