So I have been doing some testing with the MHW3bomber shaker vs WDT. I did six tests for each- 3 with a light roast and 3 with a medium roast. The sample size was based on a power analysis of the data by LH, giving a sample size of 5 for 80% power at alpha 0.05. I shook for 15 seconds with the shaker, 18 gm of coffee aiming for a 1:2.5 ratio and a constant flow rate of 2-2.5 ml/s. I experimented on each pair on different days. Also, the pattern was alternate- Shaker first, WDT second on day 1, WDT first and shaker second on day 2, and so on.
Please see the link for the data. Data
There was a highly statistically significant difference between the 2 techniques. Of course, I cannot minimise bias as I performed the test and made the coffee. Another potential source of bias- I optimised the coffee with the shaker first. However, grinding finer or increasing the ratio to extract more did not improve flavour or EY.