eagle tree help...testing

[speed demon]

I have a rustler and two combos. One a 5000mah 4S air thunder and a 2200kv medusa. Two a 6S dymond 4000mah and a medusa 1600kv. I got the eagle tree today and want to test the difference between the two combos as far as amp draw. The two combos will be ran on the same 23/76 gearing and on a large parking lot. Questions do I try and drive as close to the same as possible? Does it matter if I run the packs all the way to LVC? Any other info on how to get accurate ratings would really help. Thanks.