The first two seasons was terrific. Season three started strange and ended on a weird note. ***Spoiler Alert*** When they had Arturo killed off, the show went downhill and I lost interest in it. I stopped watching it after the third season. I was disappointed that the series went from great science fiction to politically correct sub-themes and poor writing.
The chemistry of the original four characters would be difficult to recreate. In my opinion, the writers failed by introducing Maggie Beckett as a main character to replace Professor Arturo. Her personality is abrasive and I tire of the sexual innuendoes between her and Quinn Mallory. My philosophy is: If it isn't broken, then don't fix it.