What are the differences between iZi Flex S FIX and iZi Flex FIX i-Size?

iZi Flex S FIX is a slightly scaled down version of the premium iZi Flex FIX i-Size that was launched in March 2018. iZi Flex FIX i-Size has 4 features that iZi Flex S FIX does not have: the SIP+, PAD+, adjustable recline positions and the lapbelt guider. All other aspects, e.g. the space-adjustability or the seat dimensions, are identical between both seats.