Although they keep getting closer, the Ibike is clearly not as accurate as a good "real" direct measuring power meter. The question is, is it accurate enough? That'll depend on what you use a PM for. For example, I don't look at my 5sec power numbers much, other than to dispair at how pathetic they are. For my purposes- 5 to 20 min intervals, entire climbs, and tracking TSS, it might be just fine. For someone who wanted to see the difference between different aero setups, no way (unless you pair it with a direct meter, then it'd be awesome).