if you are making sub 500whp and dont want to tune yourself, Crome is fine. It does everything S300 can that matters.

If you are into tuning your car yourself, S300 is much more user friendly, easier to understand.

S300 lets you write directly to the board, thats why it costs soo much, you install an entire board into the ECU.

CROME is nothing to be scared of, i recommend it to almost anyone because for the price you cant beat it.