I also watched it last weekend and enjoyed the setting (Barbican, city etc)
Agreed, Rebecca looked old. This also confused me initially, I wasn't sure how she fit in with her two friends.
All the murder and mystery was a bit BS, but I loved observing Hanna/Meghan and also the Spanish girl and the police officer.
I thought it was very telling how cut-throat Rebecca was and that she told a lie to protect the marketing promise (only one match), when the police woman also felt a match with her match's brother and he felt it to - she did in fact match to both of them but was told that it was not possible.
Has anyone read the book? It is mean to be amazing judging by the reviews on GoodReads.
Certainly a very interesting idea