Higher voltage and efficiency

Yeah IMO for a comparison to be accurate, the batteries need have the same punch. IOW a 5000mah 2s would have to be compared to a 2500mah 4s, because if it's a 3000mah battery, how could it be determined what's coming from voltage, and what's coming from it just being a more powerful battery.

Tacon has a 2230 KV motor ,that is like my 3930kv motor I'm running in my Slash . I also have a pair of 5000mah 2s 20c batteries. So I'm thinking about picking one up, gearing for the same speed and testing it. Using the batteries as a 10000mah 2s setup, or a 5000mah 4s setup.
Does anyone think the KV's are far enough off to skew the results?
By data logging, radaring and temping, this setup, do you think some results can be had?
Is there a better way to test for results?

Thomas, I think his point, which is something I also want to know, is how much does the amp draw play into the need for high voltage. I think we all know that if you need 3000watts then a 2s is not going to cut it, but if you need 200, what is trully the advantage to 6s? Please if you have any input on this, state your case, hopefully with some hard data, but personal experience works also.