Product review (4 stars): Bigger and Better than Anticipated
This unit is better than we expected based on the descriptions provided by Broan.  It is quiet and powerful.  Installation and hookup were relatively easy (though it IS heavy), after we studied the electrical scheme of the hood.  Broan does not make it easy to find out what parts are actually necessary.

We obtained a Broan 336 Blower to replace the incredibly noisy internal fans of our Broan Elite E6448TSS. (Those internal fans made a HUGE hum, vibrating our entire house, at every speed. Broan Technical Support even stated to us: "It's a VERY noisy unit!" So they KNOW!)  The controller in the E6448T is the same one used in the Broan E64E48.

Bottom line:
-If you need a high-performance (over 1000 cfm) range hood, and you think noise might be a problem, seriously consider an external blower hood.
-Don't buy Broan internal-fan hoods.
-Broan external blowers are much better equipment than their internal fans.