Paul You should start a new thread and ask you quesiton there. But let me ask you a question. You have an extra $250 you feel like spending to be able to spend $60 more to use lightburn. and spend half an hour installing hardware? If so go for a c3d.
Paul, time is money go with the c3d unless you like bashing your head into finding pins soldering researching probably breaking and having to re order a board programming and firmware compiling and all kinds of crap.
Are you happy with your laser cutting projects? What makes you feel like the m2 board is lacking? Basically, why u think u need board upgrade?