I found that Carole Stennett who plays Rachel's sister Nikki would have been so much more suited for the lead role. While Beverly Knight certainly hit the right notes and nobody can argue that she is a talented singer, I found her voice too powerful and it did not remind me of Whitney Houston. In my opinion, Carole Stennett came much closer to the original. She definitely has more feeling and doesn't just rely on her strong voice.
In general, I enjoyed the musical but I wouldn't spend my money on it again unless I had visitors who were really keen on seeing it. I didn't get goosebumps or shed a single tear. What really amazed me though about this production was the elaborate stage set. Rachel's costumes, on the other hand (in particular the last two in the grand finale), were a bit over the top.
My seat was in the Dress Circle, row O. You get a good view from there. Sadly, there is no leg room whatsoever. I was shifting uncomfortably in my seat for 2.5 hours.
Be prepared to have your bags checked at the entrance. A couple of people tried to get away with videoing and photographing but were warned immediately by the staff. If you go by tube, Charing Cross station is less than 5 mins walk away, same for Covent Garden station.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.