the only difference I am aware of is the pockets. the Rolling thunder has added pockets on the sides of the top bag and I believe the front pockets are larger as well on the rolling thunder.
as someone that wants to be self reliant on tools and other needs at the lanes, the extra pocket space is worth it if I can carry all my tools and supplies.
I know the rolling thunder has really nice, large wheels. that make a difference. I have no knowledge if the streamline is the same or not in this regard.