Due to PSN being down, took the opportunity to try out the single player, got hooked as its seriously good and completed it after 2 marathon gaming sessions using the sharpshooter and move. Really good story, fresh environments and constantly changing arsenal and enemies to keep you on your toes and entertained.
One of the few games where I've actually got a real feel for some of the weapons as well when you KNOW they are powerful and accurate. The minigun being a prime example where you tear people to pieces with it with ease.
As for the sharpshooter, only weird thing for me was turning around quickly which is actually quite hard to pull off with the sharpshooter without tweeking the sensitivity settings to suit your tastes properly (which I didn't stupidly). Zooming in is a shoulder button which is far less clunky than the R3 stick button and the PS move button which is right below the trigger is nice for cover/crouching and secondary fire in vehicles etc. Reloading the weapons via the pump action part of the sharp shooter never gets old and I much prefer that over the reload button on the bottom of the "mag" chamber as you dont need to move either of your hands to do it. As for the accuracy of it, its the closest I've been to using a keyboard and move on a console game yet without actually using a keyboard and mouse! Headshot galore on killzone with camera lock mode only (whats used in multiplayer so no autoaiming) is easy as pie.
Highly recommend both the game and the sharpshooter for it