Polk LSi Speakers

[CRMA]

I have been looking at the LSi 15 and 25s online. The Polk Direct website has them for 500-900 for the pair. I have the Monitor 50s and I think they sound pretty good for me. Does the LSi line sound that much better? It talks about the clarity and attention to detail. I dont know where I can find a place to go hear them personally, so I will go by some owners personal experiences. With the built in 8 or 10 woofer, does it really add anything a decent sub wouldnt add? The monitors dont produce much LFE, but the psw450 takes over where they leave off. Any feedback or listening experience would be great!!