I have always liked Gilbert since The Good Old Days and had been dying for him and Amy to pair up! I would most probably like Chung Bo more if Gilbert played him because IMO (I am going toget killed for this) Vincent cries way too much in HOTY. I know his role is a softie but he is still a general in war. He cries and cries and cries. I think crying is not the only way to express sadness or disappointment. Gilbert would probabaly cry less if he took Chung Bo's role because he was not trained like the Taiwanese artistes who cry bucketloads at the click of a finger.
Vincent actually looks very good and sexy as a villian. His acting is superb and will handle Yelut Ho Nam easily. I think anyone who took on Yelut Ho Nam's role will be likeable because the role is just so sympathetic and cool. Gilbert just added the extra bits and made the role his. Gilbert has a natural air of arrogance around him that Vincent does not.
Anyway, all four leads are good friends with each other and even if we breakup and mismatch the couples, they don't look too bad. But would be very unhappy if that happened because Gilbert and Annie would not have a single series where they are paid up! (Soft-rice Ben and Siu Kan does not count! )