Ummmm, no
The reason why it is more accurate (arguable) is because it has its own weather station built in, as opposed to the dyno dynamics ones where you type in the various paramaters (temperature, humidity, pressure, etc). The dyno then adjusts the output power figure according to these parameters. Accuracy will be an issue, and will thus affect power figures.
I am sure that there are other features on these dyno's as well that makes em a bit different