I've dabbled in HR training too, and I think it's one of those things that's useful if you're a total beginner or trying to get back into running after a break. But for intermediate runners like myself, I'm not convinced it's a game changer. It's just another metric to track, and if you're already paying attention to your pace and how you feel, it's not like it's going to revolutionize your training.
Yeah, drama in the 5k, love it