I went back and forth with Polk and Paradigm for about two months and finally ended up with the Paradigm Studio 60s. I am very happy with them, they are every bit worth $1600. But I did quite a bit of listening at lower price levels (my budget increased drastically during my auditioning process.) Overall, I preferred the Paradigm sound to the Polk sound, but that's just me and everyone has a different set of ears(I hope mine aren't deficient at the frequencies of the crash cymbals I used to stand next to in a 8'x8' practice space!)
So I'll give you in chronological order what I listened to and what I thought was special about each speaker. Let me advise you that I listen to mostly music and I'm HIGHLY critical when it comes to evaluating the accuracy of a loudspeaker as I was a musician in a "past life":
RTi6 - nice bookshelf, decent bass extension for this size cabinet. Acoustic guitar sounded a little bright, but fun to listen to.
RTi8 - Ok, these are like the RTi6 but with better bass extension, slightly more musical, probably not working as hard to produce bass resulting in more detailed mids.
RTi10 - Something wasn't doing it for me with the 10s. I thought they were less accurate than the 8s. I guess I would call them "in your face", I kept thinking to myself that I would probably like them more if I was more into HT. Not bad though.
LSi7 - Scrap the RTi6s, these are worth the extra money! Way better sound, much more relaxed in the mids. Made the RTi series seem bright. Not fair to compare them to the RTi8s, completely different loudspeakers.
LSi9 - These are even more musical(accurate/defined/dynamic) than the LSi7s, but why are these cabinets so big? Without a doubt the best Polk bookshelves and the price to match.
Paradigm Monitor 7 v4 - These remind me VERY MUCH of my old 11s. I wish I could have A/B'd these with the Polk LSi9s, it would have made for an interesting comparison.
Paradigm Monitor 5 v4 - All I remember thinking was that I preferred the 7s and I thought the LSi were a little bit more musical that this speaker. (I think I had started to steer slightly towards the Monitor 7s from the Polk RTi series, but I probably would have went with the LSi9s)
At this point, my budget bumped up. Yay for more money!
Paradigm Studio 20s - After hearing these, I knew that I was on track to buy Paradigm. Stereo imaging was WAY beyond anything I listened to previously. I liked this tweeter better than the LSis too, cymbals, acoustic guitar and string instruments seemed more accurate than with the LSis. How I would have loved to A/B these with the LSi9s!
Paradigm Studio 40s - I liked these about as much as the 60s, but I felt the price differential between the two was minimal when you consider the matching Paradigm stands. The addition of the bass driver seemed to allow the midrange to relax a bit compared to the 20s.
Paradigm Studio 60s - All the Studios I listened to were EXTREMELY close in timbre, the only differences being in midrange "presence" for lack of a better term and bass extension. Bass extension and the mids of the 40s and 60s did it for me. Of course, the 60s are only $100 more than the 40s w/stands. The first time I heard the first movement of LvBs 9th on the 60s, I was emotionally attached to these speakers. I can recall listening to giant MLs and B&W 802s of yesterday and not being as emotionally moved by the music. Boom, that was it, here's my $1600, thanks I have to run home now and listen to all my CDs again to experience them in a new way...
Before I pulled the trigger on the Studio 60s, I went back and gave the LSi15s a listen. I didn't think they were worth the money when I had the Studio 40s as a point of reference. The whole LSi line I thought was fairly accurate, but the Paradigms at the same price point were better performers.
Most of the auditioning was with Denon AVR-2805 or 3805s. I used only three different CDs when auditioning and only one track on each - Radiohead OK Computer (Paranoid Android), Deutsche Gram. 1977 Karajan recording (SWEET SACD transfer) of Beethovens 9th Symphony(First movement) and Workin' with Miles Davis (Four).
(I am a previous owner of Paradigm 11seMkIIIs. I ROCKED those speakers to no end years ago, but I have since become a more "mature" listener. I liked the neutrality of the 11s and the bass extension was more than adequate for 99% of music. After years of listening, I felt that the mids were slightly scooped. Very slightly. This was one deficiency of the 11s. I also had found that they didn't image as well as some of the B&W and Mirage I have listened to in friends homes.)
I am of the persuasion that if a loudspeaker can accurately reproduce music, it should have no problem with HT, minus LFE. For all the HT listening I've done at home, the Paradigm Studios have impressed me.
With both manufacturers, I was impressed with how much more speaker you got for $1k+ compared to $500. Having spent $900 on my 11ses long ago, I thought that $1k was a nice ceiling, with no need to go above. (Once I had the budget, I was conviced otherwise.)
So if you're into HT and not music, you can pretty much disregard the entire post! jk
-Bart
Denon AVR-3805
Sony NS-775P
Paradigm Studio 60, CC-470, SA-25s
Sony 60WF655
(You tell me what sub to buy, I am sick of subjectively auditioning these damn speakers...)