I bought a Powertap thinking that would be enough. Then I thought about wheels and hubs and such. Sold the PT, bought a new wired SRM bike (it only cost a bit more than the SRM itself). Bought a second wired SRM.

Although I race, that's in the strictest sense of the word. I enter races. I like racing.

However, I only have the power meter so I can look at the squiggly lines after the race. That's really what I bought it for, that and some tests (seems like I can finish a 20 minute test every couple years, I give up pretty easily). For me it's not much more than a quicker reading heart rate monitor.

Is it worth it? Sure, I like it. Can I ride without it? Sure, and I raced for half a season here and there without it. Did I miss it? Well, some of my hardest races I have no data, so I don't know how hard I went. I like knowing that information after the fact, although a lot of times I can't even read the screen of my SRM during the race (I often have straps over the face of the head unit).

Power meters are really what you want out of them.

For my car I bought a g-force meter. Do I race cars? No. Do I enjoy looking at the squiggly lines after a drive where I went through some turns/corners really fast? Yes.