Jakob,
Here's an airflow test of four of my canisters. The best one by far at the end of the hose is a...wait for it...upright. With a decidedly underwhelming 40" of lift, a 2013 Kirby Sentria II in canister mode sucks to the tune of 120 CFM. Proof you don't NEED high suction to attain high airflow. To compare, a $1000+ Miele C3 does 101 CFM at the end of it's hose. The Miele definitely has more suction, but the airflow is worse.
Remember: Airflow is literally the speed of the air and suction is the pressure (force) of the air. For the most part, you can feel suction easily, but not airflow (unless you put your face in your vacuum's exhaust).
Bill (VacLab)