Rewards will be strictly linear with total rshares.
I'm not particularly worried about comment farming. Not only can downvotes be employed to counter that, such accounts can also be added to popular mute lists that will likely be subscribed to by "newbies" who might potentially vote on such spam comments.
Yes, the larger impact will be that it ends the use of bots to front run for curation rewards, putting manual voters back on an even footing with the bots.