A study1 conducted by M. Radovic, E. Lara-Curzio, and L. Riester of the Metals and Ceramics Division, Oak Ridge National Laboratory, showed that the impulse excitation technique as implemented using the Buzz-o-sonic testing system, was one of the most precise and repeatible techniques available for measuring the elastic properties of materials. Some of the results are shown here.

The Young's modulus vs porosity of some alumina samples are shown below in figure 1.

E vs T

Fig. 1. Determined (a) Young’s modulus and (b) shear modulus as a function of porosity for alumina

RUS = resonant ultrasound spectroscopy
IE = impulse excitation
NI = nanoindentation
4PB = four-point bending

The important thing to note in figure 1 is the higher variance in the results for the NI and 4PB tests - as indicated by the error bars - as compared to the dynamic methods (RUS and IE). Clearly, IE and RUS gave the most precise and repeatable measurements. Note also that IE is much less expensive and much simpler to implement than RUS.
1M. Radovic, E. Lara-Curzio and L. Riester, "Comparison of Different Experimental Techniques for Determination of Elastic Properties of Solids," Materials Science and Engineering, A368 56-70 (2004)