Agree with Ryan re the utility of power for understanding my overall power endurance (during long rides), my overall fatigue (comparing power to HR), using the 3 second average, etc etc. But I also love data, so I guess it also depends on who you are and how you work.
Got a free Powertap P1S with my bike and have been using that. The only real issue is that it somehow doubles the power numbers on my watch…but since everything is worked out by percentage, it works out fine. Plus, since my FTP is pushing 600, trainingpeaks seems to think I can beat Chris Froome. Otherwise it’s worked out decently for me.