Just got back. While this will not win any Academy Awards, I liked it. It was VERY cliche', from the "plot" and acting standpoints. But I thought it was shot extremely well. On par with Blackhawk Down and The Hurt Locker. It had a very gritty "real" feel to it, and for me, the effects were not unbelievable or in your face. It could have been a war film with ANYONE as the bad guy, not necessarily aliens.
I like District 9 a bit more for the characters, acting, plot, but Battle LA was pretty good...maybe a rental.