Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

It's significantly less than a power2max though, and arguably as accurate, plus I'd only need one whereas for Power Tap I'd need to buy a minimum of two, maybe more.

Which one are you looking at?

Have a look at the DC Rainmaker review, he does say that he'd use Stages now, whereas he wouldn't when they first came out.

I was/am considering one for my Serotta, but it's yet another product that is £500 in the US and £800 here.