The treatment took place in Harvey Nichols in full view of passing shoppers. In fact the threading barely hurt at all. I felt a little bit like one half of a velcro pair - it was prickly but very fast and far far less painful than either wax or plucking. I was very pleased with the shape too - natural but a lot tidier.
The tint I was less sure about. The dye was only left on for a minute or two and when I left the store it looked fine - a shade darker than my natural brow colour and nice and even but nothing extreme. However it can't have been removed properly because it continued to develop and half an hour later I was full on Joan Crawford and not very happy. I was told to use clarifying shampoo to strip the colour out and repeatedly washed my brows over the course of the next few hours. Overall it still looks a bit harsh to me if I'm not wearing makeup.
The combined service would have cost £35 if I were paying for it. I will consider threading again if I ever feel financially flush again although it is considerably more expensive than waxing. The tint I think I'll pass on.
* V. has already used a London only voucher for a Rene Guinot facial and reports that it was 'lovely'.