The reason why we stopped liking paragraphs was because everyone bitched if their vote got rejected. There were a small handful of people reading these essays and all they got in return was crap. So nobody liked writing the paragraphs and nobody liked judging them. I really don't see that changing if we go back to it, and that's ignoring the obvious potential for bias in the system.
Well, with a panel of five readers (just the people who are leading the OU nominations), the chance for bias is severely reduced. Face it, if all five of the readers are rejecting your paragraphs, chances are that you wrote a load of crap and you don't deserve to vote anyway. Just like the votes for the Pokemon themselves, you could probably put in a "supermajority" case, where the vote would be rejected if and only if >2/3 of the panel rejected it (in this case 4/5).
In short, if a person's vote got rejected, it won't be because they're vote is prejudiced against or whatever, but because it was clear by the paragraphs that they had no idea what they were on about.