9.5 sones is definitely too loud for conversation (around 3.5-4 sones is the threshold for getting uncomfortable). However, in this price range (~$300-$400), it's pretty much par for the course. A low-power blower running "at redline" is always going to be louder than a more powerful blower running at a fraction of its speed. In other words, a 500-CFM blower producing 500 CFM (full speed) will always be louder than a 1000-CFM blower producing 500 CFM (1/2 speed). Unfortunately, with under-cabinet range hoods, there's simply no room to equip a large blower - you need a full-size wall range hood for that (or a remote blower, which would add to the cost). So, the entire category of under-cabinet hoods is stuck with either very low performance, or high noise, it's not a Broan-specific issue. In addition, the filter area comes into play. The smaller the filter area for a given airflow, the higher the speed of the air being pulled through the aperture. Higher speed = more noise.

Yes, venting directly behind will be noisier than venting upwards. Performance also suffers, and diameter of duct means a lot as well. We have two PowerPlus burners on our range, which max out at 14.5K - well under what GE Monogram, Capital, Bluestar, etc., now offer. The Broan Allure III is inadequate for my way of cooking, no matter what any salesman assured me (which they did). If I could get a Futuro Futuro in here, I'd do it, but I have very few uppers and can't afford to lose one to a chimney-style hood, unfortunately! A large problem is what kind of stove do you have, and where will the most steam/smoke/grease come from? If you have your power burners in front, the Allure won't capture a good percentage of it because it's designed for the strongest suction to occur a mere 7" from the back wall. It does a great job (on high) capturing heat escaping from the oven vents, which are on the back panel of my range. But no fan 7" from the wall is going to do a good job capturing steam/smoke/grease from a 12-qt pot on a front burner with a front edge over 14" past the exhaust duct. It is basically a poor design, built for stoves that have no power burners or power burners located on the back instead of the front. Motors are not the problem; design is what makes a hood efficient at capture or not.

Now that I'm back home, I think its a miracle I've never burned myself on that lamp -- but so far, I haven't. The rocker switch is directly in front of the knob that varies fan speed. The right side lamp is about 2" to the right of them. Somehow, just far enough away to miss. As you can see from robj's second photo, there is a small concave capture area underneath the hood where the baffles are canted at an angle. Its adequate. Sure helps to turn the hood on before smoke appears. Depending on your cooktop burner layout (and cook's height), it could help to set this hood forward a couple inches. We have 7" diameter round ducts (I'm sure there's a good reason for this, but no idea what that was). A gradual 90 degree bend to the right, then a straight shot 6 ft. out the wall. Tried running on highest speed with the baffles in and out -- perhaps a tad quieter with baffles removed, but not enough of a difference to notice, I'd say. To whine once more about those lamps: Its a trivial thing, but they symbolize how little pressure Broan must have felt from competing products, to not upgrade those ridiculous lamps to a more usable screw-in style (like a PAR20). This is not so much Broan's fault as a sign of scant incentive to improve products in a backwater industry.

Mine is from builder. It is one of Thermolec air heaters ( http://www.thermolec.com/en/productView.aspx?type=product&id=77) plus a separate current triggered flapper. The heater tries to heat the air to 15 C (PWM), activated by the air flow. It is a passive one and connects to the air return of the furnace via a 10 inch duct. It is not as sophisticated and highly performed as Kas's.