@gdnrbob,
Just to build to @ctsooner's response, upgrading from the Treo to the Quatro CT's is more than just a "speaker upgrade". It's really a system upgrade. Sure, it *is* a better speaker, but you're also now 1) bi-amping your speakers, 2) inserting a pair of powered subs into your room, and 3) EQ'ing those subs to match your listening environment. Most audiophiles upgrade their speakers because they want better sounding speakers - and are willing to pay big bucks for that betterment alone. But with the Quatro CTs, you're also making your amps sound better AND your room sound better. When you take all things into consideration, the price difference between the Treos and the Quatro CTs is easily justifyable.
Just to build to @ctsooner's response, upgrading from the Treo to the Quatro CT's is more than just a "speaker upgrade". It's really a system upgrade. Sure, it *is* a better speaker, but you're also now 1) bi-amping your speakers, 2) inserting a pair of powered subs into your room, and 3) EQ'ing those subs to match your listening environment. Most audiophiles upgrade their speakers because they want better sounding speakers - and are willing to pay big bucks for that betterment alone. But with the Quatro CTs, you're also making your amps sound better AND your room sound better. When you take all things into consideration, the price difference between the Treos and the Quatro CTs is easily justifyable.