We say that because at less than $10 per bottle from Amazon (numerous applications per bottle -- depends upon how much you have to clean and how dirty your arse is), most ardent leather care guys would likely have low expectations. After our experience, we were left wondering why we'd pay more for any other leather cleaning products.
Where this stuff worked wonders was on our well used M3 steering wheel. At five years old, and having not been cleaned very often at all (read: maybe 1 er 2 times), the wheel had the trademark used leather sheen. It's matte original form had left the building long ago.
After 2-3 rounds with the Mothers Wash we'd estimate that the wheel is at about 80% of its original, matte condition. Easily the most dramatic results of any leather cleaner we've tried.
We've found that the leather wash works best when used in conjunction with a leather cleaning brush, like the Colourlock example linked to below.
Add some microfiber towels, and you've got a potent leather cleaning package for just over $30. Can't be beat.