We have a Beam central vac. It's about 34 years old, same age as the house. Sounds like a jet engine when you start it up, but still offers decent suction. Two outlets on the main floor, one in the basement, and one upstairs. Covers the entire house.
For suction, the newer low and mid-range Beams offer 600
airwatts and 125cfm of suction. The top of the line Dyson canister vacs are only 230 airwatts. Whether it makes much of a difference I suppose depends on how far the central vac's run is. It has to pull air further, so needs more power. There are 240v models if you need crazy power, but that may be overkill.
The real advantage to central vacs is versatility. You can get tons of cleaning accessories for them. They quickly go from carpet to bare floor. They offer further reach as well, which is handy for cleaning dust bunnies on the ceiling for example. You still have to lug the hose around, but it's lighter to push around than an upright or canister. They're also quieter if you're inside the house.
Given how expensive (overpriced) the Dyson canister vacs are, I'd probably go for a central unit.