I loved this film. On first watching I struggled to see exactly when the love sparked between the main characters (thought this did not detract from my enjoyment of the film). Repeated watching has, however, provided insights into this plus other extra touches to the film I did not see first time round. I disagree with the review criticizing Debra Messing for playing a film character too similar to her one out Will & Grace. While there were elements reminiscent of Grace in this performance her character seemed gentler and less in your face, but still retained the excellent comic timing.
Dermot Mulroney was excellent as the hired escort. I'd started watching the film thinking I'd want Kat to get back with her ex rather rather than him (he looked a bit too male model for me) but how wrong I was! Dermot has a very subtle way of acting, very understated - you know, the raised eyebrows that convey loads! I also thought the performances from Jack Davenport (the Groom) & Sarah Parish (the sisters' cousin) were excellent.
I love this film. It is exactly what you'd expect from a rom-com - romance, comedy and a happy ending (similar idea to Four Weddings and a Funeral)! Some of the London accents were a bit strange but as a Londoner I gave up long ago expecting anything different in a film!!