When you kitchen Design is more minimalist, the slideout rangehood is very discreet. It also allows a little more cupboard space above it to store some of those items not used as often as the height makes it difficult to reach. Slideout rangehoods don't generally have as big air extraction rates as Canopies.
Ensure your Canopy or Rangehood is ducted out the roof or side wall if possible, to dispose of excess fumes. Laws relating to ducting into the roof space vary from State to state however it is preferable to take it outside if you can.
Canopy
Can be the feature of your Kitchen or just compliment the design. The many variations in extraction rates will be indicated by cost.
Increased cost of a canopy can be compensated by the cost to have a cabinet built to support the slideout rangehood.
Island Canopy
Definitely a feature item the Island Canopy is hung from the ceiling over an island set up. Looks great in larger Kitchens but because of its fixings is more expensive than the wall mounted version.
Silent Rangehoods & Canopies
Finally ….. a rangehood that is silent. How? The motor is mounted externally on either the roof or under the eaves, thus leaving the noise in the kitchen up to you.