I went by REI to get some things that had been on my list for a long while. One of the things I was looking for was one of those extra absorbant pack towels. On display there were many different brands of towels, and approximately no information to compare between them. So I got one of the store brand and one by MSR who made the towels my other friends own. Upon arriving home, I set about to determine which towel was better. My experimental setup was a bowl of water on a scale. First I weighed the bowl. Then I immersed a dry towel, removed it, let it drip back into the bowl, and measured the bowl again. That gave me amount of water absorbed when wet. Next I wrung the towel back into the bowl, giving me one measurement for amount of water absorbed wet, re-wetted it, getting another measurement, and wrung it again. I took the average of those three for the weight of water absorbed after being wet.

The resulting absorptions were:
REI Multi Towel Lite medium
dry: 210g wet: 120g

MSR Packtowel Ultralite medium
dry: 90g wet: 50g

The catch being that the two towels are not the same size despite both being “medium.” The REI one is 2oz and the MSR one is 1oz. So they have about the same performance per weight. And the REI one was cheaper despite being larger.