I used to have a Newton, which was the previous version of the PowerPod. Unfortunately I never compared the numbers with my 'real' power meter, but it seemed to work reasonably well. I think that as long as you understand all of the caveats of the way it measures power, it can be a useful tool. Funnily, I think that its biggest issue is that most will always be wondering just how reliable the numbers they're reading are. Another thing work considering is that if you do a lot of indoors training it won't be very useful in those instances.