Dennis Quaid plays an FBI agent who is tracking down a serial killer played by none other than Danny Glover. It's a weird casting decision, but it works. Glover goes against type, and it's fun watching him masquerade as a loutish, unmannerly sociopath. Quaid is solid, but he has a one-note character to work with. He doesn't get a chance to flex his acting muscles. R. Lee Ermey takes a low-key approach to his role as an incumbent sheriff engaged in a seedy election race. Here again, we see someone in an atypical part, as we're all used to having Ermey yell at the camera in "drill sergeant" mode.
Switchback is interesting, but at the core, it's a generic suspense thriller. You've seen it before. So have I, and yet, I enjoyed it. I liked all of the characters, I liked the anchored direction (no quick cuts here), and I liked the unpredictable twists. I didn't like the ending, which ties up a loose end by creating another loose end. That's the other thing; there are plot holes big enough to drive railroad spikes through. I wouldn't want to mention specifics because it's best to go in fresh. Even the cover art reveals too much, in my opinion.
If you fancy 90's-style "serial killer" pics such as Kiss the Girls and The Bone Collector, you may want to give Switchback a shot. Robert Z'Dar says, "This is a confusing remake of Predator 2!"