Just so we're all talking about the same thing, to me efficiency is how closely a razor shaves compared to other razors with all other factors kept equal. In other words, same prep, same blade, same number of passes.
For me it's the Fatip Open Comb, Mk. 1. Unfortunately, I cannot shave daily with that razor without incurring irritation on my neck. Second place goes to the Merkur Futur, which I sold because I just didn't enjoy using it; it's just too large and ponderous. Third is the latest version of the Muhle Rocca. It's a pleasure to use, but I wish it were just a tad more efficient. The Game Changer .84 open comb and Fatip open comb Mk. 2 are tied for fourth place.
For me it's the Fatip Open Comb, Mk. 1. Unfortunately, I cannot shave daily with that razor without incurring irritation on my neck. Second place goes to the Merkur Futur, which I sold because I just didn't enjoy using it; it's just too large and ponderous. Third is the latest version of the Muhle Rocca. It's a pleasure to use, but I wish it were just a tad more efficient. The Game Changer .84 open comb and Fatip open comb Mk. 2 are tied for fourth place.