I swear Derbys extras were no good for me.... At least in my progress. I had one extra blade sample n put it in my gillette open comb and it worked so good. Now I wanna try derby in my red tip n slim
Lesson learned! Blades in one razor May act differently in another razor
Is that a ball-end NEW or a ball-end 102 (old type)?
Glad you found a sweet-spot combination.
One I recently discovered is Feather in a Gillette short-comb NEW.
The Feather works fine in the long-comb version, but the short-comb appears to give equally close shaves while demanding slightly less care about pressure. So it's a tad faster and poses a bit less chance of irritation.
Over the past week, I found the Feather in an old-type open comb required the most attention and most chance of burn. So much for the blade-gap = aggressiveness theory! Will try in other examples to confirm.
Astras seem to work very well with NEWs and old-type alike, and seem to me a bit more effective than a Derby - but less demanding than the Feather. In case you want to explore farther in that direction.