Take a look at this article on HealsBlog where Karen explained her philosophy, which consist in getting to know their client perfectly while putting any ego on the side in order to create the most relevant and dedicated designs. They "run the practice as family" which makes them a very approachable despite their high-end portfolio.
I totally agree with this way of thinking. Good designers shouldn't be intimidating, should they ? After all, you are asking them to create your home, it doesn't get more intimate than that. So it is crucial that you feel comfortable with your designer.
Their portfolio is a beautiful mix of luxurious yet completely "liveable" designs, mostly in and around London, and each project is a feast for any design addict's eyes.