I sold mine to a buddy who now uses it daily: the Feather Popular. Mild, but really very efficient once you master the right angle and the polymer safety bars glide super smoothly as well. I could get a DFS effortlessly. One day I will get another, but until then the post-war Tech is my No. 1 daily driver.
I find that the Hone and Pils 101NE razors are mild. As to "efficient", both can be this, provided that you have adapted and honed (sorry!) your handling techniques to get the best out of them. If you don't, then you have a good way of scraping soap off your face, whilst perfectly preserving the bristles beneath.
Otherwise, I second the Krona, and a "Fat Handle" Gillette Tech with a Feather blade works well for me.
PILS. Get the angle right and it cuts like a scythe but you don't feel the blade. It's probably the only razor where my skin doesn't think it's been shaved afterward. You do need to get the angle right though, if you don't it sulks and refuses to work.