I'm just making the point that total mass (bike + rider + clothing + bottles +helmet + tools etc) is the only thing that matters for objective acceleration, so the bike weight is not super critical within the scope of what the OP is talking about i.e. less than 1 kg difference. Perception of acceleration is what magazine reviews tend to focus on, not the reality. When comparing bikes at this level, the differences are going to be more related to fit, geometry, overall compliance and ergonomics. In most cases, aero (heavily influenced by fit) is going to have the biggest influence on objective timed performance, if that really matters to the OP.