Having both the FI and C4 I say they are more complimentary than overlapping. At least one of the 'patch gods' is very active in each community. I'm a long way from be a patch ace but on the surface of things, the FI natively does Moog very well, the C4 does the best ARP i've ever heard... and I had previously been chasing Chameleon since Headhunters was released on vinyl... no longer chasing... Minor tweaks to @Kesselari 's Chameleon patch and voila ... those tweaks were probably more to do with different basses and hand techniques than anything else.