Companies in the software business often distribute requirements engineering responsibilities over several roles. Product management has overall product responsibility and performs early-phase market-driven requirements engineering. Product development implements the product and performs late-phase solution-oriented requirements engineering. Such shared responsibility provides advantages in the utilization of specific knowledge, skills, and resources, but leads to problems of mutual understanding and coordination. Earlier research proposed a negotiation process, handshaking with implementation proposals, that allows product management and development to achieve agreed requirements understanding. The process found acceptance in industry, but the relative advantages compared with traditional requirements hand-off and analysis had not been understood yet. This paper fills this gap by describing a case of measuring requirements and design volatility and an architect's requirements und...