Unfortunately I had seen a spoiler review, by accident, prior to watching this, which did diminish some of the suspense in this film for me. However, in retrospect, I don't understand many reviewer's comments about the two halves of the film (before the murderers are revealed) and them not acting in accordance with knowing they did it. I didn't see that at all, and they were clearly concerned about people knowing they did it. What did confuse me, however, was WHY they were doing what they did, and whilst there were clues, some aspects were not given and to me they were the ones that I was questioning! I was surprised at the film having seen the trailers as they seemed quite (cleverly) misleading. It is, all told, a suspenseful film in that you don't know how the nefarious pair will be caught and how many/who will survive. Though in saying that it is a little bit Hollywood and largely predictable and the twists were seen coming a mile away. Perhaps I can say that with hindsight given that I did know some plot points ahead of time but even so, to me it was obvious anyway. I guessed quite a few things and was glad how it ended up.
Hawaiian born, Timothy Olyphant was just superb, believable and constant, and convincingly teamed with Kiele Sanchez who was feisty and super-cool. I've liked everything I've seen Steve Zahn do and this was no exception, I think it showed him as a brilliant actor to be so varied, chameleon-like and in such an action role where he is usually associated with geeky characters (love him in Reality Bites). Mila Jovovich was also great - in fact all the actors were well formed, interesting and generally believable making for a good ensemble cast in a gripping action thriller. I'd have liked to have seen more of the Chris Hemsworth and Marley Shelton couple.
The SFX people did a good job with all the bloody wounds, mutilations and injuries, they were very impressive and I became quite squeamish at a few. I thought it was wonderful to see the calm, beauty and grandeur of Hawaii as a backdrop for quite an ugly story. Whilst I didn't quite get a motivation for all the misdeeds that went on, it was still a very good watch and the script was clever, witty (making fun of typical action film blunders, I just thought something like "he'd have run out of bullets" and the guy goes and says, "I should have been counting my bullets" etc) and intelligent. A film is always getting an extra point for referencing Cool Hand Luke!!