Training/Racing with a power tap

Does anyone have any experience training/racing with the power tap?

Pros?

Cons?

Affect on wheel?

Weight?

I will be using this for IM racing.

Cannondale Kid

cannondale kid - Here’s a couple articles about power that are worth reading.

http://www.slowtwitch.com/mainheadings/coachcorn/power.html

http://www.cruciblefitness.com/etips/IMPower.htm