2 Brick Breaks = 150
1st Superpower = 120
2nd Superpower = 75
Total = 195
So 2 Superpowers are more than 2 Brick Breaks. Also, most Scizors run S-Dance, so the drop won't matter. Go for Superpower if Scizor is Banded or running S-Dance. If no S-Dance or you do not like the stat drops, go for Brick Break.
EDIT: If you ARE NOT running S-Dance, Take Superpower, not Brick Break