I've heard a lot of heavy kava drinkers (connoisseurs, hah!) in the villages of Fiji who claim that hand-pounded kava tastes better than kava pounded with machines. This we can attribute to either:
1. The machines grinding kava to a finer powder, allowing more of the bitter-tasting makas to get through the strainer cloth or
2. The people making this claim merely being opposed to progress and new technology (it's all in the mind).
How kava is hand-pounded: