Even though my best event was the 800 if I could do it over again I don't think I would do 800 training, like ever. I used the spend the fall & winter training like a 5k guy, and lo and behold, I could still race fast indoor 800s, 1000s, miles. As soon as we hit spring it would be time to "sharpen up", but then the middle distance specific workouts would just fry me. Always ended up injured or burnt out.
I think I should should have continued training like a 5k guy but then my sharpening would come from racing 400 to 1500. That's it.