A better read is Training and Racing with a Power Meter by Allen and Coggan. Training with power is much more than "knowing" your power or being able to say I produce X watts. It is about hitting power numbers that are meaningful to you over discreet periods of time to improve VO2 Max and Threshold Power as well as others. Downloading individual power numbers into Training Peaks Software and tracking progress becomes very meaningful and motivating. Post ride analysis leads to incite on how to increase performance. This benefit even makes the SRM cost justifiable. The question becomes how many power meters can one have and which bikes to equip to have it make sense when you are paying the cost. For us, we do not ride the tandem enough to justify yet another power meter solution.

If a pedal based power solution becomes available that will work for the track, I would get two setups. Then I could easily swap pedals to the tandem and effectively set up the equivalent of four bikes with power. And BTW, the current SRM solution for a track bike is 3700 Euros if you are looking for a gee whiz factor.