This debate will go on till the end of time. I prefer tubes for high efficiency speakers. I think they bring a warmth to these types of speakers that SS doesn't. On the other hand, I prefer SS on the bottom end due to it's ability to provide the power needed on the low end. Many SS amps sound quite nice, but the ones I've heard that compare with good tube amps were all class A and expensive. The good SS amps won't sound glaring on the high end providing the speakers are up to par, but tubes definitely have the edge in midrange/vocal area IMO.