I'm a member of Proctor & Gamble's Savvy Circle. From time to time I am selected to trial products from P&G's extensive range and the Vidal Sassoon Salonist colour trial was one of them. I received four boxes of colour (and a nice thick VS towel), two blonde shades and two brunette. I used the 7/0 and have sent the other three colours out for testing by friends.
Because my hair was still quite a dark red from a previous home hair colour, I pre-lightened it, conditioned like mad and waited two days, then used the Vidal Sassoon colour. Its a bit fiddly when you are used to using a bottle to apply colour, but you get the hang of it quick enough. Even better if you have a friend applying it for you (or you for them). I found the brush method does cover the roots better, so you don't have the problem of missed patches. Especially at the back of the head when your doing this on your own.
The colour developed well and I was really pleased with the outcome. The finished colour was slightly lighter than the box of Dark Neutral Blonde 7/0 showed, but I put that down to pre-lightening my hair first. No red or brassy patches and hair felt in very good shape afterwards.
As with the majority of home hair colours now, there isn't as much product in the kit as there once was. If your hair is any length but quite short (mine is pixie cut), you will probably need two boxes.
Tip: if you use a lot of styling products, its worthwhile using a clarifying or build up removal shampoo a day or two prior to colouring. It makes a difference.
Vidal Sassoon R&D behind it.
Can be a bit messy and awkward to apply. Time from start to finish can be longer than with bottle applied colours.