A thought; since the ergos are a "custom" switch, were the sliders lubed when the switches were assembled? That can make a difference in feel. I can definitely tell that the browns on one of my POS board - which I've had apart several times, and have lubed - feel smoother than the browns in my Noppoo which is nearly new.
Likewise the clears on my Filco, since I harvested the stems and springs from a POS board, were lubed before assembly, and they feel smooth as butter.
I'd be curious to know if the straight clears you tried were lubed or not.