Most Polks to me sound very bright, analytical and just not fun to listen to for music
playback.* OTOH Infinity's Primus series sounded much mellower - but still detailed - and were pleasant to listen to......to my ears. Plus the Infinitys always seem to be on sale somewhere for some crazy low price (MSRP is $329.95 apiece).
I sit no more than 6-7 feet away..........Room size is 15x15 I think
For music anyway i.e. most pop/rock genres & in that listening situation, I think as far as the Infinitys are concerned, the 363's dual 6.5" woofers should provide plenty of bass. Of course, a sub can definitely provide potentially better-quality
bass, but I've owned stereo systems since the early 80s and I believe with some patience & placement experimentation a sub-less system can still provide very enjoyable listening sessions. Full disclosure: I own a 5.1 surround system and a 2.0 system and do
think most music sounds better bass-wise with the sub-equipped system. But the "pure" stereo system is still a kick to listen to, plus there's a certain attraction to setting up & using such a (relatively speaking) simple system.
* this was determined using my own music, bands/individuals like Beck, DJ Shadow, Weezer, Animal Collective and Black Flag.