Infinity Primus or Polk Monitor series

There is a lot on the primus owner's thread. Check it out.

I know that an audition of each is almost impossible, but really you will not go wrong with either. Both Polk and Infinity make excellent units for the price. The current sales on both speaker lines is outstanding.

This may not help much, but I'll offer you a comparison. I had a pair of Polk R50s (down a line from the monitor series, or older, not entirely sure) as my bedroom speakers for ~2 years. Additionally, I got a buddy of mine a pair of Primus 362s for his wedding, and took them out of the box to...break them in for him and make sure they weren't damaged in shipping

That said, the Primus setup definitely sounds a bit better than the R50s did. I think it would be hard to really compare the two, but if I had to, I would say the Primus set had better imaging and a cleaner sound. If you are using it for HT, you may not care as much about the imaging, but in stereo, they can sound very good. When I set up the 362s, I ran them in my living room against a pair of Paradigm Studio 60's, and although they couldn't touch the Paradigms overall, their soundstage was almost as good. I never felt like I had that kind of presence with the R50s. That said, the Monitor series is not the R series, so YMMV.

FWIW, my buddy now has the exact same system you describe and he really likes it; I've listened to a bit of material over at his place and it sounds good. At the time I bought the 362s, I thought they were the best deal going, but I'll admit I think the Monitor 60s look a bit cleaner.