I have the quintet + ksw10 + h/k 225 set up and also live in an apartment. I've only had it for a week, but I can tell you that you will not be disappointed.
I love it and am thankful my brother-in-law talked me into doing it. Also, received some nice advice/encouragement on this board from skonopa, among others.
Our test dvd was attack of the clones (the big jedi arena fight) and I was completely amazed by the sound and the effect it had in my living room. My downstairs neighbors may hate me, but only for a few hours a week
Anyway, hope this helps.
cyclones22