I already have the test equipment here (quarch), but haven't figure out what exactly to test. Any requests?
Oh, neat.
I feel like SSD power use isn't that important when the laptop is actively using the CPU or GPU to any degree, because those are far higher TDP parts. The difference between a 2W and 7W SSD isn't a deal-breaker if the GPU and CPU are pulling 10-20x more than that 5W difference.
I feel like SSD power use only matters when you have low-load situations, as this is what can have a dramatic impact on battery life - Based on my Kill-a-Watt testing, a small laptop will use (PFC-corrected) ~15W just web-browsing and a little under 25W playing back streaming video. That includes the screen backlight and fans, so an SSD with poor idle/background power draw can have a significant impact on runtime.
If it were me, I'd test once to see if there's any power draw for garbage-collection etc during S1 sleep, then again at Windows desktop maybe average it over 5 minutes of typical background disk activity, and then maybe once again streaming YT/Netflix or similar as watching shows or movies is where people often hit the limits of their battery life.