Any recommendations and / or advice would still be appreciated, but I think I have it nailed down now. Using my Lavazza beans, I keep experimenting my fineness of grind and tamping pressure until I think I have reached an optimum. I worked the grind on the Baratza all the way down to 2-B, and got to 30 - 35 second extractions at 9 bar. Just now, at that grinder setting, I ground just enough of the Johnson Brothers Twisted Espresso Blend that came with the Breville to fill the 2 cup, single wall filter basket, tamped using the Brevile tamper, and pulled two beautiful shots of espresso at 9.5 bar that resulted in the best-tasting, most balanced latte I have ever had in my life! Last night, I ordered the Espro Calibrated Convex Espresso Tamper from y'all so I can really dial-in a consistent, perfect-every-time extraction. I think I am really going to enjoy my Breville Dual-Boiler!