Price: T9: 129 USD, S7 49.99 USD.\n\nPros: Very effective.\n Quiet operation.\n Excellent build quality.\n\nCons: O so far!\n\n I recently picked these up from Amazon an I am really impressed with their performance so far. I use the S7 models to cool my Marantz SR-5015 AVR and ADCOM GFA-5400 amplifier that powers my height speakers. I use the T9 model to cool my Parasound Halo A23 amplifier used to power the mains.\n When I am listening to music or watching a movie I keep the AIRCOM component cooling units set to “on” at low speed. During music and movie playback I can’t here the AIRCOM units at all, When my AVR and amplifiers are in standby mode I set the AIRCOM units to smart mode, then the cooling units only power on when needed. The S7 and T9 units do an excellent job keeping my gear at ambient room temperature.\n The AIRCOM S7 and T9 in my opinion are definitely worth their price tags. Great “peace” of mind!