I've become radical. I've awarded a few posts with 2 merits recently. 
On the rewarding of 'normal' posts - If I have time, and I see that a guy has made a sensible post ( what I would call a useful one), I have a look at his activity. If 50% or so of his first page on the recent post list are 'useful', then I will award merits for the block.
On the rewarding of 'normal' posts - If I have time, and I see that a guy has made a sensible post ( what I would call a useful one), I have a look at his activity. If 50% or so of his first page on the recent post list are 'useful', then I will award merits for the block.