The real problem with "best soap ever" is two-fold:
1) too many variables. Brush, water hardness, lathering style, etc., etc., etc.
2) "the soap asymptote." In other words, there are physicochemical limits to what a soap lather can do. Many soaps are approaching the asymptote. Once you get to the asymptote, all the soaps that reach that point are extremely similar in terms of their properties, and unlikely to get better with more tweaks, changes, etc.
My opinion? Many of the current artisan soap bases are at or very near the asymptote. Therefore, what is the "best ever" soap for any particular wetshaver is the one that produces the best lather under his/her particular circumstances (water, brush, loading style, lathering style, etc). Or the one whose scent he/she finds most pleasant.
Which leads us back to the OP.
1) too many variables. Brush, water hardness, lathering style, etc., etc., etc.
2) "the soap asymptote." In other words, there are physicochemical limits to what a soap lather can do. Many soaps are approaching the asymptote. Once you get to the asymptote, all the soaps that reach that point are extremely similar in terms of their properties, and unlikely to get better with more tweaks, changes, etc.
My opinion? Many of the current artisan soap bases are at or very near the asymptote. Therefore, what is the "best ever" soap for any particular wetshaver is the one that produces the best lather under his/her particular circumstances (water, brush, loading style, lathering style, etc). Or the one whose scent he/she finds most pleasant.
Which leads us back to the OP.