I don't see why anyone would use a RDS/Holographic on the Tar, it has great ironsights, just wastes the first perk/no silencer.
Also, if you want to snipe using a silencer, never do it on the intervention/barrett/m14 ebr (unless it's hardcore, otherwise only headshots will be 1 shot kills), you want to use the WA2000. Silencer+Stopping Power on it is still 1 hit kill for the torso and up.
All i've been using since i prestiged is the barrett (and now that i've unlocked it, the WA2000 <3),tar or the vector. Along with either the PP2000 or the SPAS-12. I don't know why, all I used to use was the SCAR, the Intervention or UMP. I think I do prefer the setups I use now, even if they are less common.