This should be a very short comparison The C5 is not really a C5 it’s just a C4 board inside a C5 shell and it does not fit well so the batteries are stuck dangling outside, its not worth a penny more than the C4 in fact due to the badly designed casing it’s a bad option all round.
it does not offer any advancement on the C4 whatsoever, it has been made by the Chinese to dupe the unsuspecting buyer our advice is stay well away you are paying for a fancy metal box that is not all that fancy it has a serious flaw when it comes to the batteries, they are only needed once every few months and on the C5 they are on an external pack with Eproms with no indication which way they go in, so you are guaranteed to either at best you lose the pack and not be able to use the mux or at worse put them in the wrong way blowing the board.
Mercedes Benz C5 original tools do offer an incremental advancement on the c4 and has the latest protocol DOIP but the china clone does not.
the clone C5 is often sold at a higher price yet it runs the same software
our conclusion is to stay away from it or buy the more expensive actual C5 copy which is sold by us, the only reason we advertise the other is to stay competitive but we try to inform our clients of this c5/c4 issue