I noticed that all the other reviews are by male readers. In India most of the kitchen work is done by our female population and it is important to hear from them too. One important point is the noise. Please remember that any fan will make some noise and the kitchen exhausts make such a loud noise that it becomes a factor in their selection.
I have noticed that many homes do have exhaust fans but they do not use it because it adds to the problem due to its noise level. Better system will be where the fan is remote and it is deducted so the noise is minimised. The height of the exhaust where practical should encourage natural flow of exhaust from the kitchen so when there is no power to run the fan there is some natural exhaust.