I used this mixed with Herbatint 5D (Light golden Chestnut).
Pros: It covers grey very well, the colour is very natural looking, it smells OK. It is recommended by a French report as being the least toxic of permanent hair dyes, and it has no ammonia, parabens, resorcinol, toulene.
Cons: It doesn't have much red in it, so the colour was almost a plain brown, and I found it to be slightly too dark. Although after 2 weeks it started to fade a bit, and it became slightly redder and lighter. It is awkward having to mix 2 colours together, as the bottles aren't clear and see through, so it's hard to measure out how much you need. It would have been better if the 2 colours had already been mixed together, or if the bottles were clear and see through, with measuring markers on the bottles. It has a lot of PPD in it (listed 6th in the ingredients), and has peroxide (2nd) - but all permanent dyes have these chemicals in.