CicloSport HAC 4 and wattage

Does anyone use the HAC 4 Cyclometer or even better, how about CM 434…i think it is the same has the HAC but without the heart rate monitor?
(see page 62 of May issue of Triathlete Magazine)

My main question is about the wattage output indicator. I this a pretty accurate device worth buying or is the polar model better? How does the wattage compare when using Computrainer?

any info would be great!

Thanks

GH

From what I understand, the HAC4 power reading is just a WAG (wild ass guess), derived from speed and incline. There is no direct power sampling.