My turn.
I have reduced turn over to the sump a lot maybe only 3x (700GPH) using 75watts of power. However I have ordered 2 power heads that can each do 1200gph that will each use 15 watts of power.
This is on a 220G. I could easily use a FX5 and save 25watts of power, in place of the sump. I could get the exact same amount of bio media and close to the same turn over rate.
However it is worth the extra 25watts of power, because every day I look at my tank the level is exactly the same. Evaporation is lost in the sump and not the tank, in addition with the FX5 I have to stop filtration to clean the filter. On a sump I would never stop the filter just remove the mech filter media clean it put it back. I also don't have to scare my fish taking water samples.
Another benefit of a sump is universal parts, for example if an FX5 breaks you are typically SOL until you can order the parts. However if my pump dies in my sump, I can at any time buy a new pump from anywhere.
So what I am saying is yes Canisters are more efficient, however you can properly make a sump very close to this efficiency. I made mine more effective by raising the sump to the level of the overflow in the tank. I can do this since my sump is behind a wall and is never seen, you could also do this if you had a back ground in your tank,you would not see the sump through the tank.
I wont even talk about the HOB, IMHO HOB = POS. They are loud, no way around that, they splash which means more water is loss then would be lost just through evaporation. Not to mention that you are really SOL when a part breaks on them.