The refinements made here polished out an already great concept.
This game marriages third-person shooter and tactical elements beautifully, all while refining what few complaints I had about its predecessor; I especially enjoyed the multiple-difficulty setting which was notably absent in the first iteration.
The campaign was short and sweet, picking up almost immediatley after the close of the first game's. There was enough variation between squad-based missions and solo missions, though I often missed the presence of additinoal firepower during the solor missions. Short and sweet, just how I prefer my single-player games. The developers could have tacked on another few hours to fill the game, but I'm glad they (seemingly) cut out the fluff and kept this game focused.
The weapons were tight and varied, my squad capable of taking down enemy soldiers on their own, and the support offered through helicopters, tanks, remote controlled drones, and friendly soldiers (non-Ghosts) gave more variety than the last game's.
Bottom line: if you enjoyed GRAW, you'll like GRAW 2 even more, while there aren't any major improvements to cause you to enjoy this one if you didn't like the first.