I've seen some older central units that use basically a FilterQueen or Tri-Star type motor. I was expecting the power to be worse than the portable machines they shared the motor with, but even when installed in a system, at the end of a long hose and pipe system, it had better power than the portable.
Basically, while being much longer, the air passages are wider than an upright or canister, and the filter/bag setups are usually made with more surface area.
The installation itself does definitely matter here too, you could, for example, install a system with all short 90s (these are ONLY supposed to go immediately behind the inlet int the wall) for elbows... This would result in massive airflow loss and very poor performance. Use sweep 90s or two 45s and it works much better, also using a Y fitting rather than a sweep T helps.
Hoses can be the worst restriction though. I have hoses that make my massively powerful central system feel like a mediocre canister, think Electrolux Central hose here... But really, central vacs have always performed as well, or better than contemporary canisters (And I believe both canisters and centrals out perform uprights) as they have always, for the good units, had so much power that, even after the small losses that do occur, they are still more powerful than a canister. And the most important thing, the only way to be sure you really have removed the dust is not to have a HEPA filter, but ti vent the machine's exhaust out of the living area.