Thanks for the reply Vincent.
I had a go in MtoA and followed the documentation for Arnold 5 (https://support.allegorithmic.com/documentation/display/integrations/Arnold+5+for+Maya) and this is the result. I would say this is pretty close with the substance painter. Redid it with the C4DtoA. The result is not that far-off but I'll say MtoA is better with details. I reckon this has something to with the metalness parameter in C4D, but I'm not so sure. The reason is that I can still modify the IOR in C4D despite putting a Map into the metalness and modification also changes the final image. In MtoA, IOR is already locked when map is inserted.
I'm putting this issue to rest. I'm generally happy with what I came up with. Still, looking forward for other work arounds, if there are any
P.S. Make sure to follow the Allegorithmic's Arnold 5 version and not the older version. I kinda wasted my time with the older version trying to work out it.*
Result*
https://www.dropbox.com/s/p7wu4xgkweii50i/c4d018_arnold_SPb.jpg?dl=0
Yes, I would love to know what to do with the IOR value in C4DtoA.
And it is also possible to modify the base weight and other parameters, which all make the material look very different.
Also a lot of confusion about the gamma settings, should the Substance material be left on auto/sRGB/linear? Looks like you had to set these in older versions, but maybe they are done automatically in the new versions, I'm not sure.
Substance to C4DtoA (latest versions) tutorial anyone?