I've been using henna for about 7 months now, I think, and I love it. I use Jamila from HennaSooq, and I'm very, very happy with it. The lawsone content is 2.6%, and it gives me the perfect shade of red for my skin tone. Not too cool and not too warm. Even my absolutely brilliant colorist told me to keep using henna because it suits me so well. I had to stop chemical coloring because my hair just couldn't take it anymore.
Just yesterday a complete stranger walked up to me and said "your hair is the most amazing color I've ever seen. I love it! It's absolutely amazing!" That made my day.