Hi, Steve. I have not heard the S550i. Its test results show it to be an extremely powerful amplifier - much more so than the S300i - that's capable of throwing a lot of juice into lower/more reactive loads. Intuitively speaking, it sounds like it's something for you to seriously consider. Good luck.
__________________
Felix [AT33PTG/II RB600 VPI Lehmann Oppo Tascam Krell Dunlavy]
|