IMO, the Monitor7 is a great speaker for the money. I have never heard the JBLs before, but a quick look around the web tells me they are considerably more expensive. Since I haven't heard them, I don't know if they're any better than the Paradigms. Do you intend to buy a subwoofer? If you will be using these speakers for mainly HT, you will definitely need a subwoofer in order to get the most LFE enjoyment out of action movies.
If possible, listen to them side by side - then you can decide which ones you lkie more.