Running Metrics with Forerunner 570 + HRM 600 vs 970 + HRM 600

Hi all,

honestly, I'm trying since days but I can't figure out what specific metrics I will miss out when I have the combination Forerunner 570 + HRM 600 instead of 970 + HRM 600.

I will not have the Step Speed Loss metric, got it, but what else?

Will Running Economics be calculated without that specific metric?

I don't care for the ECG or Maps, the sapphire glass and flash light are nice to have but not worth the extra money for me.

Just having the Step Speed Loss missing doesn't really justify 200 € more for me, but am I missing more running-relevant metrics when I get 570 + HRM 600 instead of 970 + HRM 600?