From what I understand, the original 2x2 connectors were causing numerous problems even back on the original OEM Fuel pumps, and the flat 4 pin connectors were reported to be the GM fix. I am sure someone could even find the GM Service bulletins. That is why most all of the aftermarket pumps have now gone to the flat connector.
In any case, as you stated, most people don't invest in the good crimping tools or the good crimps. If you have these and they work for you, that is fantastic, however for the rest of us, Old Master is right on the soldering/heatshrink technique.