i have used the Z240s for years now and love them. Sea and Sea seem easier to setup though. My wife uses YS-110a and i also think that they are quality kit as wel;l but the Inon have the edge for me. i like the battery compartment and it seems that with eneloops the Z240s seem to recycle faster and they are easier to pack and travel with. and a bit wider? and switching between the two i seem to find them easier to position for CFWA. Size helps for Macro as well. I also use the warming filters as in some situations they can be a bit cold.. you couldn't go wrong with either..
good luck on that choice