"Estimated Left/Right Power: This became all the rage just prior to true left/right units coming out, starting with the Quarq RED unit offering left/right power. That platform works by essentially splitting your crank in half and assuming that any power recorded while pulling up is actually coming from the left side, whereas pushing down is from the right side. Thus, an estimation. It’s good, but not perfect. Note that even with true left/right power (below), there’s actually very little in the scientific community around what to do with the data. While you may think that perfect balance would be ideal – that hasn’t been established. And some that have looked into it have found that trying to achieve balance actually lowers your overall output. The only thing folks agree on is that measuring left/right power can be useful for those recovering from single-leg injury. The PowerTap C1, all Power2Max units, and all SRAM/Quarq models currently on the market use this method."
Från dc rainmaker angående dubbelsidig mätning. Power2max anses ju vara ett bra köp av de flesta så kör bara kör :) quarq blir alldeles för dyrt.