Only if you believe the hype.
Don't get me wrong, the Songtower's are excellent speakers. Having ran them for a few months, it is easy to understand why so many people dig on them. But, are they 'leagues' beyond 'mainstream' competitors? Absolutely not.
To the original poster: the Polk LSi-15's are pretty solid speakers, especially when you consider their age and price. That said, I'd rate the SongTower's as half a step above them in overall performance. While the SongTower's wont sound as warm as the LSi-15's, nor will they dig as deep or hit as hard.. they will sound a lot cleaner and more balanced from top to bottom. Plus, they won't require he-man amps to sing well.
Unfortunately, I have zero experience with Hyperion, so I have zero input there.