The Garmin Vector S (first iteration) the Assioma are replacing was essentially a dead end. It only spoke ANT+, and not very reliably at that. Random drop outs with both an Edge 810 and Zwift that were getting longer despite installing fresh batteries. The only reasonable Garmin upgrade path is the Vector 3S, and for an extra $150 plus/minus the Assioma's give me the Duo option.And I'm just geek enough like the idea of being able to track L vs R independently.