I am about 25 hours into the break in of new pair of LSi15's. I am driving them with an older Sony N77ES power amp (tube like and built like a tank) - capable of 270 watts RMS into 4 ohms - and the amp is also 2 ohm stable. Here are my observations so far on how the sound has changed: the treble has smoothed out, and the bass has opened up. I would also say that these speakers are very clean, coherent from top to bottom frequencies, slightly warm, tight bass, well defined treble without being edgy, and well above the performance of anything in its price class. I almost pulled the trigger on a pair of B&W CM9's, but I have no regrets about buying the Polks.