This is a good discussion (not having read the article yet). This week I discovered the Heart Rate Monitor as a tool to make me less demanding of myself. I've been running with a bunch of tall fast guys. (I'm not particularly fast among women of my height.) I don't expect to be able to keep up with them, but I do feel the pressure when they are getting smaller and smaller...until they disappear entirely and then I forget about them the rest of the run.
Since I started wearing the HR monitor, every time I start to feel like I'm running too slow, I consult it before I start to speed up. Every time, it turns out my HR has already increased. So I'm not "allowed" to speed up because I want to stay below lactate acid threshold. That gives me time to think about how I'm doing just as much with what I have as they are. They just happen to have more!
2009 Trek 7.2FX WSD, brooks Champion Flyer S, commuter bike