Primobolan is DHB with a methyl group added to C1, and enanthate instead of cypionate ester. Even if brewed perfectly they both tend to cause at least some PIP/inflammation > 100mg/ml. DHB is more potent so less mg are needed to get the same anabolism. DHB also less commonly reduces estradiol.
They also both seem capable of raising liver enzymes unlike other injectable AAS, excluding of course those derived from C17-alkylated compounds designed for oral use (winstrol, anadrol, metribolone, superdrol, etc).