if you want a sniper rifle to be "good", your gonna want to upgrade the gun. if you want it to be as high fps as bolt action rifles you may want to consitter making it semi only... but that doesnt mean the host of a game will let you play with a semi auto sniper rife that shoots 450 fps... host's call i guess.
if you want sniper/assault rifle dont upgrade the shit out of it if you plan on going qcb. the sl9 isnt a good choice for cqb anyways its to big
P.S. there are reviews look harder.