New game bought: Sniper Elite V2. Your thoughts!

[pots555]

I have traded-in a bunch of older games and, out of the blue, pick up Sniper Elite V2.  I had not read anything about it before hand, I just thought it looked cool.  So far, I have played the prologue and found it very solid.  As I made my way past some guards I distracted, my heart rate began to pick up.  When I sniped my first victim, and saw the kill cam, I was hooked.

After, I began reading reviews and players opinions on the game.  Not good.  No matter what, I won't regret my purchase, but I would like to know your thoughts on this fine game.  A few questions:

1. How long is the main campaing?
2. Did anyone get the dlc and is it worth it?
3.  Can you upgrade your rifles?

Thanks a lot!