I really like Kate Beckinsale in leather (or is it rubber?), so I was quite disappointed to find out that she wasn't in the new Underworld prequel. But then there's no reason she would be, it's set before her character is born (luckily a clip from Underworld with Kate in is shown at the end of the film). Rohna Mitra, who plays one of the lead characters Sonja goes some way towards making up for it.
Rise of the Lycans is different from the other films. Underworld and Underworld Evolution almost verged on sci-fi with their modern weapons and fast cars. Rise of the Lycans is set a few hundred years in the past and quite different, but just as good.
I don't think Bill Nighy knows how to put in a bad performance. He's superb and even stronger and more aggressive than in the other films. Micheal Sheen, now even more prominent in the story, puts in a much better performance than in the other films.
The only criticisms I have is that there isn't much of a story line and Viktor is clearly killed at the end and then turns up alive.