The current GOG "base" Omerta game includes the first 4 DLC (all DLC except the Japanese one) for the PC. Is that not the same for the Mac?
No, the mac doesn't get the Japanese Incentive DLC on GOG whilst the mac version of it is present on steam.
Oooh. I misunderstood. I thought you were referring to the other 4 DLC. I sympathize.