We purchased our BreatheSmart 45i several months ago and have had a chance to get a feel for its capabilities. It seems to work quite well. The particle size sensor is very sensitive. We have ours located in a carpeted living room. Walking by the unit will quickly register larger particles in the air and a less 'clean' indicator color will display. I do hope that Alen will provide an adjustable discharge opening on their higher end purifiers. Our 45i draws air in from the 2 sides and the bottom and discharges the purified air straight out of the top. I believe that an angled discharge would provide for greater air circulation. Anyway, we are glad we made this purchase.