HK London has a very talented and friendly staff. We go there as a family with my wife and kids as well. Mehmet (Alfonzo) is the best hair stylist I have seen in London. I have been always going to him after he first cut and styled my hair 3 years ago.
It's a nice little salon - there's no dedicated area for nails - you sit at one of the hair stations - so as long as it's pretty quiet then it's a nice experience.