slownlo,
Although I've never listened to the Polk LSi series in my home, I've auditioned them (both floorstanders and bookshelfs) in multiple occasions/locations, including friends' houses and dealer rooms.
To be honest, they've never impressed me: To my ears, the bass is on the boomy side (I can rather say it is blatantly boomy); midrange has a "boxy" coloration; and treble lacks details and airy qualities. Most importantly for me, however, they just fail to disappear sonically, period. I always hear the speakers working hard -- transparency is just not there.
That said, preferences on the speaker sound are, of course, a 100% personal thing; it is clear that the Axiom sound did not appeal to you much. Although you never described the Polk or Axiom sounds any more than "good/bad" and hence I cannot judge what aspects you really liked/disliked of them at all, your post tells one simple fact: No speakers can please everybody -- neither the Axioms not the Polks.
Incidentally, although I personally like the Axiom sound, my own 2.1 system does NOT contain any Axiom speakers -- just to tell you that I am not an all-out Axiom loyalist or fanatic, which I believe very few of the "regulars" here actually are.
