PSB Image T55's vs PSB Stratus Silvers

Which set of speakers are better?  
My system currently consists of a Yamaha Aventage 2050 A/V unit, two PSB Image  T55's for front channels, two PSB Image T55's for rear channels, a PSB Image C40 Center channel and a Klipsch Synergy 12" down firing sub. It is used roughly 70% of the time for movies and 30% of the time for music of all types. 
Tonight I was offered a pair of PSB Stratus Silvers for $350. I have never heard these model nor do I know anyone with a pair.