Apparently, i tried to look for the information for you. It looks like they are the same family, just a newer revision.
So in the newer one, it will have a different TA number and firmware version. I think the new firmware is V8790.
Both products are excatly the same except that C1 represents 1 unit pack vs C5 represents 5 unit pack sku.
C1 vs C5 mostly used by disti to order 1 unit pack or a 5 unit pack
BTW C means it is a channel sku.