Don't get why folks say it's bad against armour and to use a backup weapon for armour, cause it sure is better then the Saber against armour and I don't recall hearing folks say anything of that sort against the Saber? So yeah, it's definitely good enough against armour.
Also shocked folks hate this as a headshot weapon, because it's very headshot friendly with it's multiple shots thingy it's got going. Miss one burst, no worries, your next burst is ready to go right away.
The best class I found for this so far while messing around with it now that I finally got it to level 9, is the Geth Engineer 6/6/4/.6/4 (got to have that pet. Never again am I playing without a pet >_<). Mods are Stability & HVB. The second bullet still flies somewhere around out of the center, but not as much anymore with Hunter Mode, and like megabeast said, use hard cover for much further head shots.
But yeah, I always use some sort of stability help on these type of guns (Argus/Vindicator/Incisor/etc.), otherwise I'd be on the hate bandwagon too.
Scope works great too, especially if your kit don't got any accuracy boost, since it turns it into a sniper rifle without any hip-fire penalty. Plus turn that Ghost kit into a true Infiltrator too.