As former military, I'm particular about realism. Although this movie had it's share of cinematic liberty, for a sniper movie, it was actually quite good. As soon as I saw "Billy Zane" in the opening credits, I groaned a little. He has matured quite a bit since "Sniper"...plus, they didn't play up the role of GMSgt "Gunny" Beckett too much (the lead role is his son, Brandon Beckett), so that made it less like a sequel and more like a continuing story line. It was just a good, action-packed "heavy on the sniper action" flick. If you like military movies, specifically sniper movies, you'll enjoy it. You won't say it's the best sniper movie ever, but you'll watch it to the end without puking.
Not as good as Shooter (Mark Wahlberg), not as good as the original Sniper (Tom Berenger), but a darn close third place, with every other sniper movie falling way behind IMHO. A little too much cheese at times, but countered with some slightly comedic moments (the Russian talking about John McClane from Die Hard...yippie-ki-yay, MF'er, etc). It had it's snicker moments for sure, but pretty much action-packed from beginning to end, which I love.
Overall, a definite watch. Maybe not a "keep forever and watch again and again", but unless you're one of those people who want to dissect cinematography (really well done here), or the director's mood or previous works and how it compares, you'll enjoy it for what it is. Lots of sniper shots, lots of "Semper Fi" moments, and just a decent movie. I'd watch it again, but not anytime soon.