The curation rewards penalty period is the most interesting part of the whole Steem economy! It is the only period that has two simple yet conflicting algos, it also has a dynamic maximal point and hence cannot be maximised for every post. I'd like to see the concept extended to the full 7 days :-)
Anyway, on a more immediate note, one factor that hasn't been considered is that different tribes have different parameters for this curation-penalty period, so some voters are voting specifically for a tribe using their staked tribe tokens, but obviously their votes still appear on the Steem blockchain. So there is now a plethora of different voting algos out there.