That 1 second delay feels like FOREVER sometimes. My SDL takes just shy of 1 second, and I swear it feels like 5 seconds sometimes, especially when I'm used to the SL and the Honda which shift immediately.

Raising the idle speed will correct the slow shift to some extent because the fluid pressure is slightly higher and the pump volume greater. Could explain why you didn't notice it before fixing the top end when the idle was still higher than normal.