Well I have a ss/fire brute I've put a lot of hard work into and spines/fire without the incarnate work but is slotted very solid both great for farm runs. But obviously the brute is more efficient because of incarnate work but before incarnate I used my scrapper just as much as the brute.
Fury and Critical's kept their damage pretty much on par with each other but my brute definitely had much more boss killing power via Knockout Blow. The scrapper could kill bosses but not nearly as fast so I would change my tactics and instead of focusing on one boss I'd move on to the next group and let them soak up my aoe damage and they'd die off.
Of course this varies depending on the brutes primary but spines/fa is still does very very well for farms but unlike scraps /fa brutes can couple many primary's and still farm well so you'll see them much more often in my opinion.
Iv been offline for a few months, was wondering if spine/FA is still a farming toon or are brutes just so much better