Depends on what you are looking for. But it is good to understand the different methods of wear (rate) representation and also evaluation for both conformal and non-conformal contacts so you can make a better judgement.

For conformal contacts I  recommend the paper "Wear quantification" 

Abstract: Tribology literature shows considerable scatter in the wear rate of materials obtained by pin-on-disc type of studies. The general consensus thus far hits been that this scatter is due to variations in the material properties and experimental conditions used by different investigators. However, the present paper shows that the scatter carl also arise from the way wear is quantified by popular methods such as by m(3)/m, m(3)/Nm and so on. Therefore, an improved method of wear quantification indicated as "wear index" (WI) a nondimensional quantity, has been proposed and it is expected to reduce scatter that arises from the way wear is quantified. Evidence for the improvement has been provided from the results obtained from the experiments reported in this paper as well as those reported by different researchers. ...

For non-conformal contacts I recommend "Effect of Contact Pressure and Load on Wear of Alumina"

Links for both the papers are attached

Hope this helps

Article Wear Quantification

Article Influence of Apparent Pressure on Wear Behavior of Self‐Mated Alumina

From my point of view is better wear rate, because this response relation the wear with the time. In other words, "speak" about how the materials pair wear during the time passe. The other response is only a wear quantity.

Specific wear rate is more important compared to wear volume....................

Can you give us a little more information on the application?

Regards

Wear rate is preferred since it depend on time and speed to determine the process of wear. The temperature plays an important role when using wear rate.

in wear rate, whether the temperature or pressure plays a role.

As my concern pressure plays a role

It helps you.

Article Measuring Wear-resistance of AISI 1.7225 Steel under Various...