I do not know your mounting options, but the infinity system has a threaded insert in the back for easy mounting while the JBL's can ONLY be mounted to a wall (which it comes with). Thus, if ceiling mounting is required or considered, scratch JBL off your list.
I auditioned the JBL160's and the Infinity tss-450 and 750's myself. I too read great reviews about the JBL's and found them to be messy sounding. On the other hand, I found only a few reviews of the Infinity's but when I heard both of the Infinity's, they sounded much cleaner. Something else I liked about the Infinity system was the speaker wire mounting as they screw in as opposed to having a spring-clip like the JBL's.
What kind of receiver are you pairing them up with?