I've got 2 of the large system water proof boxes and probably 12 inserts of varying slotted foam designs...the system alone makes it worth it for me.
Oddly enough I've decided to use those 2 strictly for bass and am buying 6-7 wheatley boxes for trout. Wheatleys aren't submersible but I've dropped them in and they float long enough to grab em.
Back to the CF boxes. Again, I'm not knocking them completely. I DO find them a little heavy and bulky.