Pros and cons of metronome training

http://www.yourrunning.com/forum-metronome_training#comment-4303

Q: When training, is it best to learn to run at a pace using a metronome? Or is it more important to use a heart monitor and focus on aerobic vs. anaerobic?

Simon says:
You can't learn the fine art of pace judgement using a metronome. What you can use it for is to check and, if you need to, to improve your cadence -- your footstrikes per minute.

Learning how to run at specific paces is very useful, especially when you're racing. To do that you need to calibrate how each pace FEELS to you. And for that you'll need either a measured course, a track or a speed-distance monitor. I use a Garmin Forerunner, but am saving up for a Polar RS800sd, which as well as giving you your pace will also reveal your stride length -- and cadence!

Using a metronome will give you zero information about whether you are training aerobically or anaerobically. But then neither will using a heart rate monitor. You will have to work that out for yourself and then learn where your threshold heart rate values are.

It sounds like you would really benefit from working with a coach.