It's got a simple (and, based on my experience, quite reliable) formula with, as noted, few ingredients. I won't be without it (because a tub lasts a long time, especially if you have a few soaps in rotation), but I think some of the top artisanal soaps are as good—but also somewhat different.
If it doesn't work for you, I would suspect hard water. Unlike (say) D.R. Harris, Martin de Candre has no EDTA or other chemicals to alleviate the effects of hard water, and hard water doesn't work well with pure soaps, producing a sticky scum. If you know your water is hard, you can run the sink half full of water and dissolve in it a small pinch of citric acid, which will help. A good test for water hardness is to get some distilled water or "purified" water (from which minerals are removed by reverse osmosis), add a dollop of tap water (pure demineralized water tends to make airy lather), and use that to lather and shave. If the lather with the diluted distilled/purified water is much better, then your water is hard and the citric acid trick may be worth a try. You can find citric acid sold with brewing supplies (helps invert sugar), healthfood stores (salt substitute and prevents mold when growing sprouts), and canning supplies (prevents browning due to oxidation). Be sure to get pure citric acid (white granulated crystals), not (e.g.) citric acid mixed with pectin, which is sometimes how it's sold for canning.
Really, Martin de Candre should not have to be discarded, and if it doesn't work, it's worth figuring out why. As I said, the prime suspect would be the water.
