We have had very good luck with Charlies, and lots of people do, but also just as many people seem to have problems. I think if you have moderately hard to very hard water you are probably better off NOT using Charlies. We have slightly hard water and I add 1/4 - 1/2 scoop of borax with the Charlies, and that seems to work well.
Also some LOs have rash issues I have heard.
'ing with DH since 05/05
DD 01/11 and two long doggies