I've been thinking about getting a heart rate monitor for a while, but can't quite convince myself that it will have significant impact on my training. How much more data does a (non-elite) athlete need than time (stopwatch) and distance (online mapping)? As long as I'm trying to go faster for longer and further do I need to do more to optimize the results I'm getting? Perhaps it's because I haven't taken the time to educate myself about how an HRM is used to improve training, perhaps it's because I'm too lazy to have a structured training regime--I know about and try to mix up interval, tempo and LSD runs, but I'll be damned if I can keep to a consistent schedule--but all these Suuntos, Polars and Garmins seem more like expensive toys than useful tools.
What are your experiences? Did training with a HRM help you, even if it was just a psychological boost to get out the door every day? Where can I read up on how to use a HRM to improve my training? Any recommendations on a good model?