Personally I thought there was something that was missing from this one... something in the mood. It felt a bit like Selene had somehow lost a little bit of her edge in this one.
There were some inconsistencies which bothered me -
i.) She was a third generation, older, vampire - meaning that she was likely to be stronger than younger, 4th or 5th generation vampires who she could easily fight, even in the first movie.
ii.) In Evolution she then became a Corvinus-strain hybrid and was able to fight off an Elder; not even just an Elder, a Vampire-Lycan hybrid elder who even commented "impressive" at one point.
iii) In Awakening she is able to heal herself far more quickly than before, and has enough power to flip a truck by running in to it, and she can fight a genetically modified über-Lycan, albeit with a little trouble... yet in this one she seemed (before her resurrection) she seemed to struggle to fight off a Lycan-Lycan-Vampire hybrid. I know he is stronger than regular Lycans because of injecting Michael's blood, but still.
...which brings me to my next point: how was Marius even able to kill Michael in the first place? We know Michael escaped the Lycan run facility because Eve sees him through her eyes on the roof of the building and he's gone when they get there. We know Michael can dispatch regular lycans and vampires with ease, and can take on an Elder pure-blood lycan and win with relative ease... yet a regular lycan somehow overpowered him, killed him, and has now ended up as some other kind go hybrid?? Meh. Seems a bit odd.
With the original Elders dispatched, I would have assumed the 4 most powerful individuals in that world were (In order) Eve, Michael, Selene, and then David.
I got a bit irked with the way they dealt with her death too: it felt a bit "meh". I always felt with Selene that if they were going to kill her that it she have been bold, violent, and sudden - ditto if she was going to sacrifice herself. But instead she sort of just lands and then feebly drowns herself. What was that about?
Following her resurrection her additional abilities seem to just be blonde streaks and an ability to move fast enough to 'blur'... which was a bit confusing as we'd already seen her move so fast that it was akin to teleporting in both Evolution and Awakening... it also didn't seem to make her any stronger either. I didn't really see what the point was?
There was also a little bit too much going on for my liking: another vampire-lycan affair, another power hungry vampire trying to pull a coup, another lycan leader attempting to gain more power using hybridisation, blonde, northern "magical" vampires. There were some good-ish ideas... it's just a shame we'd either seen them before or the execution of the new ideas were poor.