I have recently auditioned the 603, 602 & 601 models with my mate "rowbos" at Audio T. Their demo room is about 12 x 20 and we used the Denon 3802 & Denon 2800MkII. Like you, I love the look of these (sorrento) which certainly helps.
We have auditioned many other speakers but the 600 series produced the best sound for my ears. I quite fancied a pair of 603s but found that the 602s (to my surprise) sounded slightly better. The bass and midrange didn't seem as clear with the 603s. Strongly recommend you try the 602s alongside the 603s to hear the difference. I bought the 602s and Denons and they are now run in and sounding great.
I have only noticed the booming bass once whilst playing Skunk Anansie (Paranoid & Sunburnt). I tried the foam bungs, but no difference. Mind you it was VERY loud, and until my house move completes they are in my study which is only 10 x 6 - so there's no choice but to have them in the corners.
Not long to wait till the move, when I'll be trying the 600/601s, LCR60/600 and their subs. Christmas should be great.
Happy Auditioning.