Having seen HHP twice and Hammond once in the playoffs, I am going with HHP. Hammond is clearly reaching its peak at the right time, but HHP has consistently beat similar teams because of their balanced game. They have a great defense and can put points on the board very quickly.
In the first Pinewood game, Pinewood led 2-0 at half and HHP was able to put three goals in the net in the first 15 mins of the second half, completely changing the dynamics of the game. In the second game, Pinewood's defense played a solid 80 mins, but HHP was able to put to free kicks in with very impressive shots. Bottom line - you need to play a great game and not make any mistakes to beat them.
On the other hand I would love to see Hammond win and will be there cheering for them and of course supporting the Pinewood boys in their quest for number 5.
Also I am not sure I agree with the comment that Hammond's region was obviously much tougher than HHP/Pinewood's. Clearly Hammond was not a #3 seed and Pinewood took them to overtime in a great game. But call me biased - I am a parent / fan, so what do I know!