Some of the previous posts have stated that both pilots can log actual and total time in IMC. This is incorrect. The only way two pilots can log actual is if one is a cfii giving dual given.

Safety pilot time is highly disregarded as a means of time building. I disagree with rickair about it being an industry standard. Safety pilot time is meant for you and a friend to go get current flying instrument approaches in VFR conditions. It is and will never be considered a legitimate way to build multi engine time.