All I have to say is: HOLY SH*T!!!
I got the flea market LSi9's from frank Z today, unhooked my LSi25's, cranked down the LSiW all the way down, poured myself a gin and tonic and busted out the Massive Attack. Mezzanine is the perfect workout for a new set of speakers- if they have any weaknesses, that album will make them glaringly obvious. I settle down in the sweet spot and start the music.... and think "Dammit, I must have not turned the sub off" I get back off the couch, go over to the sub, and it's off. When they say the LSi9's go to 38 hz, they aren't kidding- they can hit low and sound great 5 minutes out of the box. My 25's must have taken a month to get dialed in just right and I'll kill anyone who messes with my settings. About that time my roommate comes in and says "Oh, those speakers are so cute!!! THey're like little brothers to the big ones. When do we get to hear them?" Me: "Uhhh, we're listening to them right now" Her: "Bullsh*t!" Yeah, so now she wants them for herself.
The good news is that these rock. The bad news is that I'll be the world's biggest ******* if I just use these for rear channels like I'd planned.
Are they as good as the 25's? No, the 25's hit lower and harder, but take a lot more work, money and floorspace. However, the 9's are some of the most affordable bookshelfs that come anywhere near that level of sound quality.