I would say that for the money the JBL is better. I have not had much experience with the rockford but I have heard nothing but good about it. My opinion would be the JBL b/c you get quality and more power for less money.
My friend has a 1200.1 jbl hooked up too two alpine R's. He also had a 800.2 Rf hooked up too them. The JBL sounded alot cleaner and louder. The Jbl is cheap and sounds great.
go with the jbl i just got mine last week and i am still waiting for my other 12 but i hooked that thing up to one R sereies 12 with the gain all the way down and it still had the power to melt the solder on the speaker