Quote Originally Posted by Cassandra_Cain View Post
I've compared the published power curve for the KK and found it within 10% of my powertap readouts, so I'd say it is useful and reasonably priced. If I didn't have a PM, this method would be my choice.
10% is actully a pretty big deal if you're training with power. Let's say you're doing threshold intervals (2 x 20s) at 240 watts. Training 10% below (at 216 watts) would put you far below threshold so you wouldn't be getting training benefit. Training 10% above (at 264 watts) would probably be impossible so you wouldn't accomplish your workout. This differential would be even more noticeable with shorter intervals since you're at a higher rate of power.

But since you have a PT, why don't you just use that on the trainer rather than replacing or adding another power device? That's one of the nice benefits of a PT -- you can use it on the trainer as well. Of course, you need to know how to adjust your power zones for inside training since they'll be a bit different.