My thoughts, I think 20 rep over 24 hours is too many...but 5 is too low. Something around 12 would be a good idea, along with 10 negs, which I would also change, to no more than 1 every 24 hours.
It was almost interesting to see people put a little more thought into reps when they thought they only had 5 each. The point is there's too much rep if people are able to play abusive games with it, whatever the case may be.
As far as "sorry posters" go, think about it bones. Which posters do you see with red splats? The shittiest posters this board has to offer, like Yidnar and Ariux.
If a poster is that bad, a near daily amount of negs from a wider group of people will keep their count low...and if they're only seen as bad to 4 or 5 posters with elite rep counts, they'll be safe from red splats from a small group hitting them a couple times a day, which is as it should be when you consider the size of the forum.