Personally, I don't think that it's fair to judge a regional as the "hardest" before it happens. You never know what might happen, who might jump out from nowhere, or who could pull a huge upset. Teams come in and out of regionals, and who knows what some of the more advanced teams could be saving for the championships?
Also, what would be the criteria for a "hard" regional? Would it be the one with the highest scoring average? The closest difference between last and first? The most teams? How can this be assured before it actually happens?
My 2 cents (plus one dollar for the egg-cracking bet

),
Daniel