Ribble advertise this chain as being compatible with Tiagra 4700 but all other retailers say this chain is mtb specific, anybody have a definitive answer for this?

It will work with tiagra but not as well as a 4601 would

Thanks simon, does that mean slightly sloppy changes or something else?

Having not tried it I can’t give a definitive answer, sorry. I can’t imagine the difference would be huge though. FWIW, Shimano have abandoned separate chains for road and mtb with 11spd.