Product review (2 stars): A Good Light
I live in a condo and the HOA did not allow me to install a hood which vents to the outside, so my only choice was to go ductless, and after looking around a little I bought this one based on price and style.  It was not hard to install, the instructions are straight-forward.  Also, this one is not exclusively ductless---you can connect a 7" diamter vent exiting vertically from the top or a 3x10" rectangular vent out the back.

Contrary to what some may say, in the ductless configuration a hood like this one does nothing for air quality.  If you think otherwise you are only fooling yourself.  The hood's replaceable carbon filters perhaps catch some grease, but I still end up having to clean above the unit every month to remove a thin layer of oily scum.  The carbon filters do not eliminate odors.  All the moisture generated from cooking is simply getting blown by the fan up towards the cabinets and ceiling above the unit.  The purported 300cfm is laughable---at the highest speed it hardly pulls in half the smoke from grilling steaks (not that it makes any difference, air- quality-wise).  However, if you can run a duct to the outside, consider going with a 600cfm one at least (taking into consideration duct length and back-draft, of course).

In short, the only thing I like is the clean, modern design and the bright lighting (4 halogen bulbs, two brightness settings).  That's basically what you're buying here.

One last thing: Recently, Vent-a-Hood has come out with a ductless hood and filter that they claim really filters odor and absorbs moisture.  But at over $2k, it wasn't an option for me.  Those with no other choice but to go ductless may want to take a look at it, though.