Hello, I have just added 2 H/K PA2000 units to power up my front and surround speakers (Mordaunt-Short floorstanders). I have been hapilly using a H/K AVR430 receiver for over an year now and I've always thought it had a very good performance. My first priority has always been hi-res multichannel music (SACD and DVD-A) so, after seeing several posts on these forums about how great separates are, I've decided to give it a try. And I'm glad I did! Even if the PA2000 amps are most popular in multi-room applications, they are also great as hi-fi amps. After adding these units, the improvements were obviouous even at low volumes: tighter bass, more open and natural soundstage and soooooo much more detail. Even if H/K receivers have great amps, they cannot compare to separates, and the good thing is that you don't have to go too high in range/price in order to have an immediate improvement. My AVR430 is only powering my center speaker now and since the receiver only has to work with one channel, the clarity/volume/detail of the center have also improved. So in case you're wondering if you should invest in external power amps, stop wondering and do it: it's worth every extra penny you pay for it! Have Fun!