EL-34 vs 300B based integrated amps

I've heard el-34 called the "poor man's 300B". Well, I'm running a Cary SLI-80 in triode mode with EL-34's and it sounds lovely. What kind of increment in sound quality could I expect by moving to an SET integrated, such as Cary 300-SEI or one of the ASL 845 or 300B SET's, Sophia, others...

My speakers are Silverline Sonatina II's 93db 8 ohm - I think 10 or 15 watts would cut it, am I dreaming?

Thanks,
Art