This specific Mom's Expertise is about Yogi Nursing Mom tea. I did not use that brand, but rather I used Traditional Medicinals Mother's Milk Herb Tea. I think they are similar.
I noticed a very licorice flavor to the tea that I had to get used to, but I did grow to enjoy it. I don't think I ever drank the recommended three to four cups a day, but rather had one or two. I was trying to keep my supply up with pumping, and I found the tea to be helpful. I also tried fenugreek supplements and instant oatmeal in the mornings--I was kind of desperate, as many low-supply moms are. I was able to make enough milk with the help of these things as well as drinking lots of water.
Did the tea make the only difference? I can't speak as to that, but it was an easy option to try.