I am neither arguing for or against, just that delayed ACK probably isn't the only reason for the connection to become sluggish. A typical page makes dozens of

I am neither arguing for or against, just that delayed ACK probably isn't the only reason for the connection to become sluggish. A typical page makes dozens of requests, these are packets to be uploaded, if the uplink is saturated, the latency should increase, I'd expect that to affect the time it takes to render the page.