I stop on the side of the road to charge and chamber check my rifle(SOP states we run rifles in patrol ready/ condition 3) and don a small go bag on the way to any rifle-worthy call. My thought is that doing an armor switch out would only add 30 seconds or a minutes to this procedure. I learned early on that making scene and then charging the rifle is wrong as you want as situations are dynamic and you want as few things to worry about when you make scene.
Would I deploy hard armor on any call? Probably not, it would be call dependent. I try to run my gear very lean/simple in my patrol car and not get carried away with extra widgets. I'm still on the fence about hard armor the logistics of deploying it being worth carrying it.