I was able to hear the Polk LSi7 today matched with the Onkyo C-S5VL SACD Player and A-5VL Integrated Amp. They surprisingly work very well together.
I was able to compare it to the pricier B&W CM5 as well, partnered with the same gear.
The LSi speakers sounded best on-axis (fully toed-in and facing the listener), and this is probably because ring radiators are known to roll-off quite a bit off-axis. The CM5s on the other hand sounded a bit shrill-on axis, and preferred being pointed straight forward.
The Onkyos sounded brighter and snappier when connected digitally (we were playing plain-old Redbook CDs), and matched the LSi7s better in this configuration (improving PRAT). The CM5s were a bit too forward and fatiguing with this setup, and sounded much better with an analogue connection (more relaxed sound, and with more weight on vocals). The SACD Player and the matching Integrated Amp have different DACs and supporting circuitry, which may be the reason for this variance.
With the ideal setting for both speakers (toed-in and connected in digital for the LSi, and aimed straight-forward and connected in analogue for the CM), both were spectacular speakers for their respective price points. I'd be very happy with either.
I was most surprised with the Class-D amp, though. Had I not known that I was listening to a PWM amp, it would've been quite indistinguishable from a typical Class-AB amp. The output was clean, and the amp didn't show any sign of stress while driving these speakers.
Green technology has come a long way. It's like a guilt-free way to enjoy music.
Thanks Marc and James!