If you measured their volume with a db meter they would probably be within a 2 or 3 of each other.
Choose which ever one sounds best to you for your real world application & musical environment.
Fender is soon to release an all new re-engineered & redesigned Rumble series this week at Winter NAMM.
The current Fender Rumble 150 is a solidly reliable road-worthy & gig-worthy performer that sounds great with wonderfully rich lucious well defined tone. Plenty of bottom end umph & volume for bar gigs. It also just happens to be the best selling bass combo on the planet.
This will be replaced by the new Rumble 200.